Marina Bay Sands Hotel

The Marina Bay Sands is the world's most expensive hotel in Singapore, and with a world's largest outdoor pool at 55th storey.
"The infinity pool on the roof is in the 'SkyPark' which spans the three towers of the hotel. The platform itself is longer than the Eiffel tower laid down and is one of the largest of its kind in the world.
Infinity pools give the effect that the water extends to the horizon. In reality, the water spills over the edge into a catchment below, and is then pumped back into the pool. The pools have two circulation systems. The first functions like that of a regular pool, filtering and heating the water in the main pool. The second filters the water in the catch basin and returns it to the upper pool. "