Tracking mountain gorillas in Uganda, swimming with whale sharks and cycling across the beautiful Himalayan mountains: all these make for once-in-a-lifetime holiday experiences.
But just as thrilling is a day spent rowing on England's most famous river, according to a new Lonely Planet guidebook.
The traveller's bible has compiled a new book of the world's great adventures, and among them are six sites in the UK. Rowing or even kayaking along the Thames is described as "like sitting on a conveyor belt watching living history pass you by on both banks… a gallery of architectural evolution, meandering majestically through rural and city life".
Ambling along England's south-west coast is also recommended, as the "cliffs are immense and varied, ranging from outcrops steeped in Arthurian legend to Jurassic remnants thick with fossils".
Further north, adventurers might enjoy mountain biking in Coed-y-Brenin in Wales. This was described as a "foliage-knitted landscape, with mountain-top views that make your heart skip, crashing waterfalls and a rugged topography carved out by glaciers".
The rest of the natural attractions listed sound even more adventurous. The Three Peaks Challenge is in the new guide, and involves climbing Britain's highest peaks in one day: Ben Nevis in Scotland, Scafell Pike in England, and Snowdon in Wales.
Caving in the Peak District of Derbyshire is said to be a great chance to "channel your inner goblin", while daredevil tourists could do "coasteering" in Pembrokeshire, South Wales. It sounds harmless enough, but entails jumping from, swimming alongside and scrambling from seaside rocks.
The guide recommends that rowers begin their journey down the Thames by starting in Lechlade, Gloucestershire, but advises: "This adventure can give you serious blisters."