Located in the city of Turda, right in the middle of the historical region of Transylvania, Salina Turda is an ancient salt mine which previously served as a cheese storage facility and a WWII bomb shelter (to protect that sweet, treasured cheese). The mine is so old that no one's really sure when it was built. The perfect spot for a "sci-fi theme park"!
It may surprise you to learn that some people in Romania aren't happy with how this historical-site-turned-fancy-underground-carnival has been managed, but they're being too shortsighted. Once the apocalypse hits, the mine's Ferris wheel, mini golf course, ping-pong tables, bowling lane, spa center, and boat rides will offer a welcome distraction to our future grandchildren while nuclear winter reshapes the surface 400 feet above.