As Britain prepared for the 75th anniversary of D-Day on 6 June, visitors travelled in huge numbers to pay their respects at the Normandy beach landing sites. Back in England, Portsmouth on the south coast was the assembly point from which much of the invasion force sailed – and the city was the focal point for UK’s commemoration.

The event took place while US president, Donald Trump, was on a state visit to the UK – and, on 5 June, Portsmouth hosted Queen Elizabeth II, Trump, the UK prime minister (for a few more days) Theresa May and other heads of state, including French president, Emmanuel Macron, and German chancellor, Angela Merkel, to mark this occasion.

More than 300 D-Day veterans sailed to Normandy in northern France on MV Boudicca, a ship chartered by The Royal British Legion to Normandy for the anniversary itself on Thursday, escorted by a Royal Navy vessel. Altogether it is estimated that 2 million “remembrance tourists” visited the beaches at Normandy to mark the 75th anniversary this year.

D-Day 75th anniversary: In Pictures Show all 42 1 /42 D-Day 75th anniversary: In Pictures D-Day 75th anniversary: In Pictures Heavy artillery is fired after a France-US ceremony at the Normandy American Cemetery and Memorial as part of D-Day commemorations AFP/Getty D-Day 75th anniversary: In Pictures French elite acrobatic flying team "Patrouille de France" fly over after a France-US ceremony at the Normandy American Cemetery and Memorial as part of D-Day commemorations AFP/Getty D-Day 75th anniversary: In Pictures President Trump, First Lady Melania, French President Macron and wife Brigitte watch the fly over after a France-US ceremony at the Normandy American Cemetery and Memorial as part of D-Day commemorations Reuters D-Day 75th anniversary: In Pictures Army vehicles head to head into Arromanches in Normandy on the 75th anniversary of the D-Day landings PA D-Day 75th anniversary: In Pictures Canadian veteran Don Deon poses with a container filled with sands of the Juno beach during the international ceremony to commemorate the 75th anniversary of the D-Day landings AFP/Getty D-Day 75th anniversary: In Pictures Canadian veterans attend a D-Day commemoration event prior to the international memorial ceremony on Juno Beach in Normandy AFP/Getty D-Day 75th anniversary: In Pictures Canadian Prime Minister Justin Trudeau (R) and French Prime Minister Edouard Philippe lay wreaths during the international ceremony to commemorate the 75th anniversary of the D-Day landings AFP/Getty D-Day 75th anniversary: In Pictures A commemorative parachute descent takes place over Sannerville, France during commemorations for the 75th anniversary of the D-Day landings PA D-Day 75th anniversary: In Pictures A commemorative parachute descent takes place over Sannerville, France during commemorations for the 75th anniversary of the D-Day landings EPA D-Day 75th anniversary: In Pictures Allied World War II planes flypast during a memorial service at Bayeux War Cemetery in Normandy Getty D-Day 75th anniversary: In Pictures Amphibious vehicles depart from the beach of Asnelles in Normandy as part of the D-Day commemorations AFP/Getty D-Day 75th anniversary: In Pictures French Rafale fighter jets fly over the Normandy American Cemetery at the end of a France-US ceremony to commemorate the 75th anniversary of the D-Day landings AFP/Getty D-Day 75th anniversary: In Pictures Bishop Jean-Claude Boulanger leads a memorial ceremony at the Cathedral of Bayeux, Normandy EPA D-Day 75th anniversary: In Pictures Emmanuel Macron and US President Donald Trump walk on the red carpet during a France-US ceremony at the D-Day commemorations AFP/Getty D-Day 75th anniversary: In Pictures MV Boudicca sets sail from Portsmouth, flanked by Royal Navy ships as it heads for Normandy EPA D-Day 75th anniversary: In Pictures British veteran John Prior stands among the graves of fallen British soldiers during a Service of Remembrance at the Commonwealth War Graves Cemetery in Bayeux, Normandy AFP/Getty D-Day 75th anniversary: In Pictures Len Perry, 95, from London, holds a D-Day 75 wreath while from Portsmouth to Normandy ahead of D-Day commemorations PA D-Day 75th anniversary: In Pictures Pipe Major Trevor Macey-Lillie of the Scots Royal Artillery plays on the Mulberry harbour in Normandy to mark the exact moment when Allied Forces landed on D-Day 75 years ago Getty D-Day 75th anniversary: In Pictures Crew of HMS Northumberland practice their salute as they prepare to take part in a sail past to honour D-Day veterans off the south coast of England AFP/Getty D-Day 75th anniversary: In Pictures A flypast of the Red Arrows, during the commemorations for the 75th Anniversary of the D-Day landings over Southsea Common, Portsmouth, Hampshire RAF/EPA D-Day 75th anniversary: In Pictures D-Day landing craft veteran, 94-year-old Ted Emmings of The Royal Navy, walks past a villa in Arromanche that is adorned with a photograph of him and other veterans Getty D-Day 75th anniversary: In Pictures US Second World War veteran Tom Rice takes part in a parachute drop over Normandy, France AFP/Getty D-Day 75th anniversary: In Pictures Pipe Major Trevor Macey-Lillie of the Scots Royal Artillery plays on a Mulberry harbour in Normandy to mark the exact moment when Allied Forces landed on D-Day 75 years ago PA D-Day 75th anniversary: In Pictures Military re-enactors look on as 280 paratroopers take part in a parachute drop onto fields at Sannerville, France Getty D-Day 75th anniversary: In Pictures Theresa May and Emmanuel Macron arrive at a France-Britain ceremony to mark the 75th anniversary of the D-Day landings Reuters D-Day 75th anniversary: In Pictures German soldiers stands next to wreaths of flowers during a ceremony at the German war cemetery in La Cambe, Normandy AFP/Getty Images D-Day 75th anniversary: In Pictures Military vehicles line the beach at Arromanches in Normandy, France, ahead of a day of events to mark the 75th anniversary of D-Day PA D-Day 75th anniversary: In Pictures Crosses of remembrance placed alongside a Union flag at dawn on the beach at Arromanches in Normandy, France Getty D-Day 75th anniversary: In Pictures US President Donald Trump makes a speech in Portsmouth AFP/Getty D-Day 75th anniversary: In Pictures Prince Charles, Queen Elizabeth II and US President Donald Trump look up as aircraft perform a fly-over AFP/Getty D-Day 75th anniversary: In Pictures Pipers of the 4th battalion Royal regiment of Scotland play AFP/Getty D-Day 75th anniversary: In Pictures British Royal Navy Chef Edward Baker (left) and Warrant Officer Jon Boreham, standing proudly in front of their D-Day 75 landings cake EPA/MOD/Crown Copyright D-Day 75th anniversary: In Pictures epa07627898 A handout picture provided by the Britihs Ministry of Defence showing Personnel from The Rifles, 16 Air Assault Brigade and Veterans pay tribute to those who secured Pegasus Bridge 75 years ago in Normandy, France, 05 June 2019. Approximately 280 paratroopers, including 130 British troops from 16 Air Assault Brigade and 150 from the French Armyâ€™s 11e Brigade Parachutiste, carried out a commemorative parachute descent onto fields on the outskirts of Sannerville. In the early hours of 06 June 1944, the same fields served as Drop Zone â€˜Kâ€™ for the 8th (Midlands) Parachute Battalion, who destroyed bridges to restrict German freedom of manoeuvre. World leaders are to attend memorial events in Normandy, France on 06 June 2019 to mark the 75th anniversary of the D-Day landings, which marked the beginning of the end of World War II in Europe. EPA/Cpl Jamie Hart/BRITISH MINISTRY OF DEFENCE/HANDOUT MANDATORY CREDIT: MOD/CROWN COPYRIGHT HANDOUT EDITORIAL USE ONLY/NO SALES Cpl Jamie Hart/BRITISH MINISTRY OF DEFENCE/HANDOUT EPA D-Day 75th anniversary: In Pictures French President Emmanuel Macron and Prime Minister Theresa May attend an event to commemorate the 75th anniversary of the D-Day landings, in Portsmouth AFP/Getty D-Day 75th anniversary: In Pictures Performers dressed as female soldiers take part in an event to commemorate the 75th anniversary of the D-Day landings AFP/Getty D-Day 75th anniversary: In Pictures People in period dress at the Pegasus Bridge in Normandy, France PA D-Day 75th anniversary: In Pictures Britain's Queen Elizabeth II, Prince Charles and U.S. President Donald Trump and other world leaders meet for an event to commemorate the 75th anniversary of D-Day, in Portsmouth, Britain June 5, 2019. Jack Hill/Pool via REUTERS POOL REUTERS D-Day 75th anniversary: In Pictures British Royal Navy members watch Red Arrows flight display during an event to commemorate the 75th anniversary of D-Day, in Portsmouth, Britain, June 5, 2019. REUTERS/Toby Melville TOBY MELVILLE REUTERS D-Day 75th anniversary: In Pictures A Commemorative Parachute Descent takes place over Sannerville, France, during commemorations for the 75th anniversary of the D-Day landings. PRESS ASSOCIATION Photo. Picture date: Wednesday June 5, 2019. See PA story MEMORIAL DDay Parachute. Photo credit should read: Jane Barlow/PA Wire Jane Barlow PA D-Day 75th anniversary: In Pictures Britain's Queen Elizabeth II, accompanied by The Prince of Wales, pose for a formal photograph with leaders of the other Allied Nations ahead of the National Commemorative Event commemorating the 75th anniversary of D-Day, in Portsmouth, England, Wednesday June 5, 2019. Back row from left: Slovakia Deputy PM Richard Rasi, Poland PM Mateusz Morawiecki, Canada PM Justin Trudeau, Luxembourg PM Xavier Bettel, Norway PM Erna Solberg, Belgium PM Charles Michel, Czech Republic PM Andrej Babis, Australia PM Scott Morrison, Danish Ambassador to the UK Lars Thuesen. Front row from left: Governor-General of New Zealand Patsy Reddy, President of France Emmanuel Macron, Britain's PM Theresa May, Prince Charles, Queen Elizabeth II, US President Donald Trump, President of Greece Prokopis Pavlopoulos, Chancellor of Germany Angela Merkel, Prime Minister of the Netherlands Mark Rutte. Commemoration events are marking the 75th Anniversary of the D-Day landings when Allied forces stormed the beaches of Normandy in northern France during World War II.(Jack Hill/Pool via AP) Jack Hill AP D-Day 75th anniversary: In Pictures epa07627906 A handout picture provided by the Britihs Ministry of Defence showing paratroopers landing onto fields on the outskirts of Sannerville, Normandy, France, 05 June 2019. Approximately 280 paratroopers, including 130 British troops from 16 Air Assault Brigade and 150 from the French Armyâ€™s 11e Brigade Parachutiste, carried out a commemorative parachute descent onto fields on the outskirts of Sannerville. In the early hours of 06 June 1944, the same fields served as Drop Zone â€˜Kâ€™ for the 8th (Midlands) Parachute Battalion, who destroyed bridges to restrict German freedom of manoeuvre. World leaders are to attend memorial events in Normandy, France on 06 June 2019 to mark the 75th anniversary of the D-Day landings, which marked the beginning of the end of World War II in Europe. EPA/Cpl Jamie Hart /BRITISH MINISTRY OF DEFENCE/HANDOUT MANDATORY CREDIT: MOD/CROWN COPYRIGHT HANDOUT EDITORIAL USE ONLY/NO SALES Cpl Jamie Hart /BRITISH MINISTRY OF DEFENCE/HANDOUT EPA D-Day 75th anniversary: In Pictures Canadian Lt.-Gen. Richard Rohmer talks with Prime Minister Justin Trudeau as they take part in the veterans reception as part of the D-Day 75th Anniversary event in Portsmouth, England Wednesday, June 5, 2019. Queen Elizabeth II and world leaders gathered Wednesday on the south coast of England to honor the troops who risked and gave their lives 75 years ago on D-Day, a bloody but ultimately triumphant turning point in World War II. (Sean Kilpatrick/The Canadian Press via AP) Sean Kilpatrick AP

It’s easy to understand why so many people want to travel to see the major sites of what is, after all, one of the defining moments of the Second World War in western Europe, especially for any veterans or for the families of those who risked and sacrificed their lives. But there are also those who find the idea of visiting places linked with such death and destruction to be a little macabre. There have been reports that Chinese authorities are keeping tight security around Beijing’s Tiananmen Square on the 30th anniversary of crushing of student protests in 1989 in which hundreds were killed.

“Dark tourism” is a growing market. Whether the whole point of a holiday is to visit all the battlefields of Normandy, or whether it’s a side trip on a visit to Poland to take in Auschwitz – and people have plenty of good reasons to take a detour to this appalling death camp, not least as an educational experience – many people, at least once in their lives, decide to skip the beach resort and opt instead to visit dark tourism sites.

Dark tourism (also known as “black-spot tourism”, “morbid tourism” or thanatourism – after the Greek word “thanatos” meaning death) was identified in the 1990s. It is defined as “an attraction for places associated with death”. Researchers have found the trend difficult to accurately pinpoint as tourists may not necessarily realise they are visiting a site identified as a “dark destination”. But more than 2.1 million people visited the concentration camp at Auschwitz in 2018 while the 9/11 memorial in New York attracted more than 6.8 million visits in 2017.

The notorious Alcatraz prison in the US attracts an estimated 1.4 million visitors each year. And, interestingly, given the widespread perception of the health risks involved, the site of the 1986 nuclear disaster at Chernobyl in Ukraine is also becoming a popular destination for the curious.

Following the huge success of the recent television series about the disaster, you wouldn’t bet against visitor numbers to Chernobyl increasing from the estimated 50,000 people who visited in 2017. The same trend is identifiable at the site of the 2011 nuclear disaster at Fukushima in Japan, which received an estimated 17,000 visitors in 2018.

Tourists at the Slavutich town and Chernobyl nuclear power plant museum in 2016. (EPA)

The reasons that people give for visiting these dark tourism sites are many and varied. They can include wanting to understand one’s family history and paying respect to relatives. There is also a desire for empathy or identification with the victims of atrocity or wanting to see a significant site for the purpose of education and understanding. Of course, sometimes, there is an element of voyeuristic attraction to horror.

Sadly not everyone approaches these sites with the respect they deserve. We live in the era of the “selfie” and, despite being obviously inappropriate, there have been reports of hordes of tourists queuing to take photos of themselves at the 9/11 memorial. This, in turn, has led to calls for “selfie sticks” to be banned from Ground Zero. Similarly, visitors to Auschwitz have been asked to stop posing for photos while balancing on its infamous railway tracks.

Whatever their reasons for visiting sites associated with suffering, death and grief, many people find their visits cathartic and fulfilling. There’s no doubt that among the many people coming to Portsmouth – or travelling to the battlefields of France – for the 75th anniversary of D-Day there will be many for whom it is the first chance to pay tribute to a parent or grandparent who sacrificed their lives for a greater good.

So for anyone else who might be drawn to these places out of a sense of curiosity, or simply because it is a “bucket list” destination, remember that for many people you are treading on sacred ground – so walk softly.

Liz Sharples is a senior teaching fellow in tourism at the University of Portsmouth