The world's first floating Apple store is located at the Marina Bay Sands (MBS) Mall, in the Marina Bay area of Singapore. The store was opened in 2020 and the designed was inspired by the Pantheon in Rome, where an oculus located at the top of the dome provides a flooding ray of light for the store. The interior of the glass is also lined with custom baffles, each uniquely shaped to counter sun angles.
I only recently visited the store, despite it being open for about 2 years. The dome can be accessed through the basement store entrance within the MBS mall or through the walkway at the boardwalk area. I must say that the interior of the dome was really well lit just using the natural sunlight and it was spacious too. It's definitely a nice store to come to buy your Apple products.
Here's a couple of photos that I took within the store while I was there.