This week on Foreign Correspondent Eric Campbell goes inside Berlin's Jewish diaspora in his report, "Homeland," and asks why so many Israeli's are settling in Germany.

Why choose to live in the place where your people's extermination was conceived, planned and directed?

It's the question facing the 13,000 or so Israelis who have started new lives in Berlin - and who, if Hitler had had his way, may never have lived at all.

It's a bit like dancing on his grave – and I like dancing. So why not? – Shirah Roth, Israeli comedian

Israelis in Berlin are now among the world's fastest growing Jewish populations, to the dismay of some compatriots who sense a betrayal. But these mostly young Jews aren't forgetting history. Holocaust reminders – memorials and Nazi-era architecture – are all over Berlin.

Creepy is part of life. To see life actually growing out of this death, that's fantastic – Shirah Roth

For young creatives like Shirah or musician-journalist Ofer Waldman, the magnet is Berlin's chic arts scene, its cultural medley and free thinking. As an early arrival in 1999, Waldman stood out.

It was like, ‘You're a Jew?' It's like, "Oh my God, we've never seen a living one' – Ofer Waldman

Waldman runs a group that promotes equality with Arabs. He realises he is a beneficiary of Germany's lingering guilt.

Being a Jewish Israeli here, we have a louder voice because of the past. That's a privilege – Ofer Waldman

Berlin's Jews do face a rise in European anti-Semitism, which has spurred Germany to introduce tough new laws against hate speech. But fears of hate crime are, for many, outweighed by a weariness of life in Israel – its perpetual war footing, cost of living or social expectations.

It's back in Israel where reporter Eric Campbell finds Avi Binyamin, 32, who grew up in an ultra-Orthodox family.

I was supposed to be a rabbi by now, with five or 10 children - Avi Binyamin

Instead he went secular and became a gym instructor. Now he is packing his bags for Berlin. He looks forward to a more open-minded society.

Even if we are forced to live by the sword here in Israel… I'd want us to educate our children that it's not the default position, that there are also other ways - Avi Binyamin

Avi's Israeli girlfriend has already settled in Berlin and awaits him there. His little brother will follow him soon.

Jack and Laura Dangermond spent their honeymoon in a pup tent on a remote and spectacular stretch of southern Californian coast. They were students, idealistic and broke.

We both fell in love with that place – Jack Dangermond

Over the next 50 years the Dangermonds grew into billionaires, and all through those years they witnessed the unabating march of suburbia up and down the coast. Their old honeymoon haunt became part of a vast property owned by a hedge fund that develops coastal real estate.

We just thought, ‘Well, we just have to do this' – Laura Dangermond

So Jack and Laura spied a chance and swooped, shelling out $225 million to save for all time a 10,000 hectare tract of pristine coast and its hinterland of oak forests, hills, canyons and grasslands.

I didn't believe what I was hearing. This was a big piece of good news – Mike Bell from The Nature Conservancy, the environmental NGO which was handed the land, its biggest gift ever, by the Dangermonds

Jack and Laura Dangermond are private people who rarely talk to media. But they open up to Foreign Correspondent about how they pulled off this big green deal, and why. They hope their gift will inspire similar acts, big and small, and there is urgency to their message.

Time is running out. It's not dark yet but it's late in the day – and people are going to have to move to do this kind of thing in small ways and large ways all over the planet, really quickly – Jack Dangermond

Now they're challenging Australia's richest people to take a lead as well.

I want everybody in Australia getting this idea. I want those who really have large means to look at the amazing places in Australia before it's too late. And everybody else in Australia to plant one more tree, protect one more thing, to play at all levels - Jack Dangermond

The Dangermonds' conservation coup has come against the run of play, with the Trump administration seeking to roll back environmental safeguards and open up new territory for commercial development.

As North America correspondent Zoe Daniel discovers, Jack and Laura are no left-wing ideologues. Their environmental passion is founded on the hard data that drives their business. Founded nearly 50 years ago, their company ESRI leads the world in digital mapping, its software used by 350,000 organisations to predict flash floods, ease traffic snarls, help the homeless or plot the next Starbucks.

I like maps. They're a kind of language, the language of geography, the language of human activities, the language of understanding – Jack Dangermond