Located in Romania’s historical Transylvnia area are the Salina Turda salt mines. Visitors are able to not only tour the ancient mines, which were built without the use of explosives, but also to play a game at the bowling alley and mini golf course, take a ride on the ferris wheel, sit in the ampitheater or take a ride in a boat on the underground lake. The attractions all cost extra, but with the exception of the ampitheater and the sport field, it’s doesn’t cost much.
As a bonus, the air in the mines are good for one’s health, and many visitors go for the health benefits.
The salt mines, now considered a museum, have three different caves and can take several hours to fully explore. Just remember to take a jacket, because the mines are pretty chilly.