A routine inspection turned into a stunning underground discovery when explorers followed a forgotten pipe into a vast river cave system. The find revealed flowing water, natural chambers, and ...

Their huge size is peculiar and has forced scientists to throw out their pet theories on how planetary lava tunnels form.

Six itineraries to see the best sights - These plans pack a punch, with some of the most famous sights in the world – in Portugal, Spain, France, Ireland, the UK, Germany, the Netherlands and Italy – ...