This is the Entertainment Venues area at Lunaria Emporium, where you can walk through all my main ballrooms, clubs, and lounges. All of them include the decor and furniture that you will see inside each one, or you can find the decor separately in the main store building. These structures tend to be large and complex with a mixture of mesh and prims, and they make heavy use of materials textures which can only be seen with higher graphics settings enabled. Remember to use Shared Environment to see the sky setting shown above.
All of these venues can be found on the Kitely Market here:
https://www.kitely.com/market?cat=50600&store=13957705, and can be delivered directly to your inventory on your grid.
If you don't mind hypergridding, all venues are 20% off Kitely Market prices if you get them directly from my main store.