For Laora Tuominen, the ultimate diving experience is not found off the Mediterranean coast or in a Caribbean lagoon, but hidden underneath the depths of the noisy city of Budapest. While the baths of the Hungarian capital are known throughout the world, only few venture into the labyrinth of caves that form Budapest's thermal underworld. The never ending twists and turns of the city's intestines have attracted thrill-seekers since the opening of an underground diving centre in 2015.