Have a shallow swimming pool, where you can introduce various kinds of aquatic life.
Also add several different LED TVs on the floor where people can play Netflix, Youtube etc.
Then charge people to float in the pool with a snorkel while enjoying the wildlife, watching movies etc. Multiple people can watch a TV like a theatre.
You can charge for extras like aromatic oils, bubbles, Fish Bodycure etc.
@maanitm has this been in Shark tank?