Image caption The Mountain of God or Ol Doinyo Lengai - is part of the Great Rift Valley in Eastern Africa

Trying to pick the most significant places in history is not an easy task when there are so many contenders. But History of the World presenter Andrew Marr has narrowed it down to five.

Africa's Great Eastern Rift Valley

Running through Tanzania and Kenya, this is where the human story really begins, the earliest signs of Homo sapiens and our predecessor hominids, and it's therefore where we should go back to when thinking about that great original migration out of Africa, and across the rest of the world, which happened 70,000 years ago.

We are all ultimately from the same family. We are all Africans. (And for those who think the BBC's awash with money and sent me to do the History of the World so I could visit all the places I wanted to, I should point out that I have never been there.)

The Yellow River

Image caption Giant gushes of water are released from a dam to clear up the sediment-laden Yellow River and to prevent localized flooding

This turbulent, explosive river, "China's Sorrow" is where we find the beginning of Han Chinese civilization, as tribes and villagers are forced to knit themselves together in order to dig channels to stop the regular and disastrous flooding.

Find out more Andrew Marr's History of the World continues Sunday 14 October on BBC One at 21:30 BST

Reveals the decisive moments that shaped the world we live in today

Rivers turn out to be absolutely vital for human social development, and we could equally well choose the Euphrates, the Indus, the Nile, or even the Volga, as examples.

But we are living through a time in world history when China is rising again, and it's both useful and interesting to knit Chinese history back into the world narrative after a couple of centuries when Western condescension and ignorance (and Chinese indifference) has rather pushed it aside.

The parallels between the Han empire and the Roman one, co-existing for centuries, are remarkable, for instance - and it is still impossible to understand modern China without understanding Confucius.

Athens

Today, poor Athens is the scene of violent social protest, fast-increasing poverty and rising political tension, which were all present before, and even during, her Golden Age in classical times when she produced the philosophers, the architects, the political thinkers and the poets who in turn shaped all Western civilization.

Take a short car or bus ride to the coast nearby and wander on the sandy, pine-wooded shoreline where the Battle of Marathon was fought in 490 BC, and where the Athenians' citizen army defeated the vastly numerically superior forces of Persian tyranny.

Ancient Greek democracy The ancient Greeks famously invented democracy

The word Demokratia meant 'people-power'

meant 'people-power' There's a theory that the word was coined by democracy's enemies - members of the rich and aristocratic elite who did not like being outvoted by the common herd Source: BBC History What was Greek democracy actually like?

It's still the most important battle in Western history. One of the very few markers left is a little mound, or hillock, nearby. It's in a smallish triangle of grassy land, not much bigger than a children's park and surrounded by roads. But inside that hillock lie the remains of the Athenians who fought and died at Marathon.

It choked me up when I first saw it because of its spectacular and moving lack of grandeur - no winged gods or angels, no marble, no pompous inscriptions, just a simple pile of earth.

These are again days of Greek agony and instead of constantly blaming them for not working hard enough like the Germans, we should help by continuing to go, to spend money there, and show our friendship.

I'm afraid I also think the time is right to send back the Parthenon frieze or Elgin Marbles from our wonderful British Museum. They need a real boost just now and we are in a unique position to help.

Berkeley, Gloucestershire

Who is the Briton the world should most revere? There is an obvious case for William Shakespeare, another very powerful one for Charles Darwin (my particular hero) and a different argument for Winston Churchill. But we need to put Edward Jenner, the Gloucestershire doctor who discovered vaccination, right up there as a prime candidate.

He was a true child of the Enlightenment and a product of the free-thinking, inquisitive culture of late 18th Century England. His experiments with cowpox would have been illegal today, and had him harried by the popular newspapers for child cruelty - for he deliberately infected a young labourer's son, James Phipps with cowpox and then with smallpox.

Nor did he try to repeat the experiment, or use normal controls, as any modern scientist would. He just published - a treatise which proved almost instantly popular, being read out at dinner parties and admired by foreigners as diverse as Thomas Jefferson, Napoleon and the Russian Czar.

Smallpox had been one of the great scourges of the human race, a disfigurer and a huge killer, particularly of children. Jenner's breakthrough meant it was eventually eradicated - and the United Nations declared it had gone in 1980.

We can plausibly claim that Jenner saved more human lives than any other person in history, and that on this basis he is surely a candidate for greatest Briton. And it all happened in the sleepy, green, rolling backwaters of Gloucestershire, still a great place for a stroll.

Los Alamos, New Mexico

Image caption Robert Oppenheimer is known as the "father of the atom bomb"

It was here, of course, that the United States' Manhattan Project split the atom and created the atomic bombs which would then be dropped on Hiroshima and Nagasaki.

The man who led the project, Robert Oppenheimer, was a liberal-leftish intellectual who was fascinated by Eastern religion, by art and by morality, and yet he ended up working hard to calculate the exact height at which to detonate his bombs so they would burn to death the maximum number of civilians, including children.

He spent much of the rest of his life pondering what he had done, having - apparently - reacted to the first successful test explosion by quoting to himself Vishnu, from the Hindu scriptures: "I am become Death, the destroyer of worlds."

Mutually assured destruction kept the Soviet Union and the US from engaging in full hostilities during the Cold War and to that extent the philosophy behind the ultimate weapon "worked".

But nothing stays still and it is still too early to regard what happened at Los Alamos as "just history". If you think this story's over, you know more about Iran, Pakistan, India and North Korea than the rest of us.