- This is not the world's first underwater hotel. There is a smaller underwater hotel in Florida, and more underwater hotels are being designed and built around the world.
- The train is supposed to be able to transport 1,000 people at a time.
- August, 2003: Hydropolis was announced.
- December 27, 2008: Arabian Business reported that the long delayed Hydropolis project may be built after all. The developers planned to announce a building timeline in early 2009.
- August, 2009: MEED reports that the stalled plans for this project were being looked at again.
Watch more: Great 9 Wonders Of Dubai
