Its primary function was originally as a communications hub, but these days it has become a major tourist attraction, with attractions including a Formula One motor racing simulator and pony rides.
The highlight (quite literally) for most people is the views, which are accessible either from the observation deck or the revolving restaurant.
Neither can be described as a cheap experience. The observation deck is now packaged in with other attractions -- the starting prices is 45 ringgit for adults, and 30 ringgit for kids. Better value family packages are only available for Malaysians.