The best way to get to know a city is to meet the locals. That's the idea behind travel show Lonely Planet: Six Degrees of Separation (Discovery Travel & Living, Tuesdays at 10pm). 'If there's only six degrees of separation between any of us,' says Asha Gill, the extremely enthusiastic presenter, 'then all you need to start your journey is a single point of contact' - as long as the point of contact has interesting enough friends, which, on Six Degrees, they invariably do.
This week Gill travels to Dublin to prove there's more to the Irish capital than James Joyce, Guinness and stag weekends. There she meets a pagan artist, a busker, a burlesque performer-cum-cowgirl, an Irish historian and raconteur, the organiser of 'The Most Beautiful African Girl in Ireland' beauty pageant and an entrepreneur.
Other cities covered in the series are Istanbul, Tokyo, Rio de Janeiro, Miami, Taipei, Perth, Bangkok and Kaohsiung. They're whirlwind tours (there's a lot of speeded-up camera work) and the sights are incidental, but you do see a side of each city that you probably wouldn't find in your Baedeker or Rough Guide, or even your Lonely Planet.
Six Degrees might inspire armchair travellers to get up and go, but Adventure Challenge: Trapped in the Land of Fire and Ice (A1, Monday at 9.30pm) is likely to make them grateful to be sitting snugly at home.
In 1875, an Englishman and his Icelandic guide, Paul Paulisson, were the first to cross the Vatnajokull, in Iceland, one of the world's biggest glaciers. Now Paulisson's great grandson, Ingvar (below left), with a team of Icelandic, American and Taiwanese fellow adventurers, has decided to retrace his great-grandfather's steps. Paulisson crossed the glacier during the summer, whereas Ingvar and his team are attempting it in the middle of winter, and the landscape is constantly changing due to the volcanic activity under the ice. 'Some people like to play golf. I like to do this,' says Ingvar.
The weather is so atrocious that often all the viewer can see is white with a few fuzzy figures moving slowly across the television screen. When it gets too bad for the explorers to proceed, they don't sit around waiting for the blizzards to pass; there are plenty of potentially hazardous sub-glacial volcanic caves to explore.
Towards the end of the expedition, they set themselves one more challenge: to scale the Thumall, a 100-metre lava edifice thought to be the leftovers of a volcanic eruption. The mountain is sheer, wet and black, and covered in loose rocks.
'Cool!' says one of the Americans.
While Ingvar and his team are exploring the sub-glacial volcanic caves, Bob Brier, an authority on mummies, is grubbing around beneath the church of San Lorenzo in Florence, attempting to solve a 400-year-old murder mystery in the first episode of Mummy Detective (ATV World, Tuesdays at 10.05pm).
From the 15th century to the 17th century, the Medicis were the most powerful and influential family in Europe. 'Richer than the Rockefellers ... they bankrolled the Renaissance and ignited the Reformation,' enthuses Brier. But like most incredibly rich, powerful and glamorous families, they had their dark secrets.
By unearthing and studying their bones, Brier attempts to find out whether - as rumoured - the teenage sons of Cosimo I de' Medici were brutally murdered or whether they died of natural causes. Brier's discoveries are a constant surprise and this is more gripping than any modern forensic drama. The animal kingdom is just as bloody, as the fabulously filmed Triumph of Life: The Eternal Arms Race (National Geographic, Monday at 10pm) illustrates. Since life began, the behaviour of all creatures has been influenced by their need to hunt or escape. The humble North American tree frog tadpole has a clever trick up its sleeve while crocodiles seem to have got it just right - they're large enough to eat anything but too large to be eaten. They probably would have done very well for themselves in 16th-century Europe.