Durian is a large tropical fruit with spiky exterior and very pungent smell

but these days in Singapore, people are as likely to mean the Esplanade Theatre/Concerthall complex

the spiky skin of the two blobs being made up a series of sun-rain shades for the actual exterior: 

 It is said that with the 70 storey Swisshotel behind, the blobs look like a giant fertility symbol

and the recently revealed scene from the other side after some construction fencing got removed