Two gritty teams of hobbyist cavers attempt to break records for the longest and deepest caves in Canada.

Flooding drives families from their homes. There's a rush to extract a crashed mountain biker before dark, and a man with dementia goes missing. A team member puts her cardiac training to the test.

The railway in northern Mexico known as "El Chepe" took a hundred years to build and travels through the spectacular Copper Canyon region.

Despite the challenges of rapid urbanization and a complex geo-political backdrop, the people of Istanbul are striving to make their city more just, peaceful and liveable.

This tour through the South Island's best scenery starts at Greymouth, exploring its historic mining past before moving on to Arthur's Pass National Park and the Waimakariri Gorge.

Joanna arrives in Iran and explores the engineering marvel of Fin Garden, as well as breathtaking mosques and temples. In Yzad she discovers ingenious ways to keep cool in the heat.

The citizens of Antwerp are collectively making the city and its neighbourhoods more sustainable, more democratic and more livable.

Beginning in Leon and running through the Basque region, this mountain and coastal route in northern Spain is also a gastronomic tour exploring a range of local delicacies.

The economy of Canada's oil capital is diversifying - and so is its population. An increasing number of Calgarians want a livable city that favours sustainability.

Susan visits the spectacular Orkney Islands, where she sails past the tallest sea stack in the UK and visits an ancient Neolithic village.

Starting in Tirano in northern Italy, this rail journey climbs up through the Italian Alps to the roof of Europe - Zermatt, the gateway to the magnificent Matterhorn.