Resort in a Blimp Hanger

This massive structure was once used to house airships, but has been converted into an indoor resort. Located in Eastern Germany Tropical Islands features an indoor rainforest, hiking paths, waterslide, hotel rooms, restaurants, and a beach. Wonder World takes us inside.

This instantly made me think of The Truman Show. Considering how much they've crammed in, it still doesn't look particularly spacious. How big of a set would you need to pull something like The Truman Show off in real life?