On a torrid August day in Hiroshima’s Peace Memorial Park, lotus flowers were blooming in the pond surrounding the Peace Bell. A party of elementary school children in their bright yellow hats lined up to toll the bell; all visitors are welcome to do so, and its hopeful sound regularly booms out across the park. While they waited their turn, the children pointed excitedly at the powder-blue dragonflies darting among the blooms.

These flowers have great symbolic importance in Japan. At temples throughout the country you’ll see statues of Buddha seated in a lotus blossom. The way the exquisite flower grows out of the mud at the bottom of a pond symbolises how Buddha rose above suffering to find enlightenment.

The city rose from the ashes to forge its own renaissance

But the lotus flowers in Hiroshima’s Peace Memorial Park have added significance, reflecting how the city rose from the ashes to forge its own renaissance. In August 1945, at the end of World War II, US forces dropped an atomic bomb over the city, killing tens of thousands of people. Hiroshima was a charred wasteland, and people widely believed, based on the words of Dr Harold Jacobsen, a scientist from the Manhattan Project, that nothing would grow, or live, in the city for 70 years.

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But then a remarkable series of events ensured that Hiroshima would also go down in history for far more inspirational reasons.

First, by autumn 1945, weeds began to sprout from the scorched earth, confounding the expert’s predictions. The following summer, oleanders bloomed. Camphor trees – many of them hundreds of years old – sprouted new branches. Their recovery touched the hearts of local people. The oleander and the camphor were later proclaimed Hiroshima’s official flower and tree, cherished symbols of the city’s resilience.

Meanwhile, help poured in from all over Japan and abroad, from street cars to get the town up and running to trees to replace the vanished greenery. A temple in Wakayama Prefecture even donated a complete 16th-Century pagoda, a gesture of spiritual solidarity. You can see the orange pagoda today, rising above the maple trees at Mitaki Temple, one of Hiroshima’s most serene spots.

But the key step in the city’s regeneration happened on 6 August 1949, with the enactment of the Hiroshima Peace Memorial City Construction Law. This law was the fruit of persistent efforts by local residents, particularly mayor Shinzo Hamai. At Hiroshima’s first Peace Festival in 1947, Hamai set the example for all future Hiroshima mayors when he proclaimed: “Let us join together to sweep from this Earth the horror of war, and to build a true peace.”

Accordingly, the 1949 Construction Law didn’t envisage simply rebuilding the city. It completely reimagined Hiroshima as a Peace Memorial City “to symbolize the … sincere pursuit of genuine and lasting peace”. For the first time in world history, an entire city underwent efforts to devote itself to the promotion of peace. It’s an ideal that Hiroshima’s residents still strive for.

As a symbol of this wish, Peace Memorial Park was created in downtown Hiroshima on the banks of the Motoyasu River. This area of more than 120,000 sq m, previously the city’s commercial and residential centre, is home to more than 60 peace-related monuments and facilities, most notably the Peace Memorial Museum.

On the opposite bank, the skeletal form of the Industrial Promotion Hall was preserved as an expression of hope for the eradication of nuclear weapons. Today, this building – the untouched ruins still as they were after the explosion – is the city’s spiritual heart. Officially named Hiroshima Peace Memorial, most locals simply call it genbaku domu, or A-bomb Dome.

“It’s a symbol of the importance of everlasting peace,” said student Ayaka Ogami. “There is nothing else like it in the world.”

It’s also a Unesco World Heritage Site, visited by more than 1 million tourists a year.

The word ‘peace’ is everywhere in Hiroshima. There’s Peace Boulevard, a 4km-long avenue lined with trees and stone lanterns. On this same street, opposite Peace Memorial Park, stand the Gates of Peace, a series of 9m-high glass arches with the word ‘peace’ inscribed in 49 languages. The motorised rental bicycles are called ‘peacecles’. Elsewhere, from many points in the city, you’ll see the Peace Pagoda glinting atop Mt Futaba, the silver stupa containing ashes of the Buddha, donated by Mongolian Buddhists.

“Out of respect for the people who worked so hard on Hiroshima’s reconstruction, we ought to make this city a beautiful and great place to live,” said Maiko Awane of Hiroshima Prefectural Government’s Tourism Promotion Office. That’s why, apart from the many monuments to peace, you’ll also find Hiroshima to be far greener than the average metropolis, with abundant parks, gardens and riverside walks.

But Hiroshima hasn’t just created a peaceful environment in its own city. It also promotes peace worldwide via countless initiatives, from travelling exhibitions about Hiroshima’s past to Kids’ Peace Camps where elementary and junior high school children can learn about peace. Hiroshima’s Museum of Contemporary Art awards an annual prize to works that help spread the message of harmony. Peace Arch Hiroshima, a collaboration between Hiroshima Prefectural Government and other local entities, stages “Message of Peace” concerts in the city that aim to connect people around the world.

“We are striving to send a message of peace from Hiroshima to the world and create a system that continuously supports peace-promotion activities,” said Hidehiko Yuzaki, Hiroshima Prefecture governor and Peace Arch chairman.

At the heart of all these efforts is the Mayors for Peace project. Founded in the 1980s, it was the brainchild of then-Hiroshima mayor Takeshi Araki, who dreamed of transcending national borders and encouraging cities to work together for peace and a nuke-free world. Tackling poverty, hunger and other global issues is also on the mayors’ agenda. So far, 7,469 cities in 162 countries and regions have signed up; 16 new cities joined in October 2017.

It is the duty of all the people in Hiroshima Prefecture to ensure that what happened on that fateful day is not forgotten and never repeated

Peace education starts early in Hiroshima; elementary schools hold an annual Peace Week, where students are educated about Hiroshima’s past and the importance of peace. During their summer vacation, many students volunteer to guide foreigners around Peace Memorial Park.

“I hope to be able to pass on Hiroshima’s story to many people in the world,” said high school student Saki Nakayama. Moe Kanazawa, a graduate of Hiroshima University’s Peace and Coexistence Course, which studies ways to prevent conflict and find resolution through international and local cooperation, goes further: “I think it is the duty of all the people alive today in Hiroshima Prefecture to ensure that what happened in Hiroshima on that fateful day is not forgotten and never repeated.”

Having lived and worked in Hiroshima for nearly 20 years, I still get asked by folks if it’s a grim place to live. Far from it, I always answer – because, as local yoga instructor Izumi Sato told me: “The image of Hiroshima’s reconstruction is much more powerful than that of its destruction.”

The image of Hiroshima’s reconstruction is much more powerful than that of its destruction

Today’s Hiroshima is a bright, welcoming place, blessed with an enviable location on the shores of the Inland Sea, with its maze of misty islands. On the other three sides are mountains. Six rivers run through it, earning Hiroshima the nickname the ‘City of Water’.

Visitors invariably leave here with an overwhelming feeling of admiration and respect for the tremendous character of Hiroshima’s residents, who resolved to pick themselves up and start all over again, turning their tragic experience into a force for good in the world. Many visitors also say they experience a notable spike in their levels of empathy, compassion and altruism. It’s what you might call ‘the Hiroshima Effect’.

As Awane said, “I hope many people visit Hiroshima… and think about the importance of peace.”

Places That Changed the World is a BBC Travel series looking into how a destination has made a significant impact on the entire planet.

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