Iceland
The Silfra Rift running right through the middle of Thingvellir Lake is the tectonic boundary between the North American and Eurasian plates. The glacial meltwater is pure and crystal-clear, creating excellent visibility and emphasising the striking underwater scenery.
This is the only place in the world where you can dive between two tectonic plates and two continents – the rift between Eurasia and America. The water is never warmer than 4°C (you’ll need to wear a drysuit) and the glacial meltwater is so clear, it makes some divers feel dizzy.
Family-friendly snorkelling trips are available in summer, so non-divers can go too, and it all takes place in the beautiful surrounds of the Thingvellir National Park.
Adult price: £80
Min age 6
Good for age: 8+
Duration: 4-8 hours