Torre de Collserola is a uniquely designed tower located on the Tibidabo hill in the Serra de Collserola, in Barcelona, Catalonia, Spain. It was designed by architect Sir Norman Foster, and built in 1991 for the 1992 Summer Olympics. It features a pod for floor space like many towers but uses guy wires for lateral support like a mast. Mainly used as a TV and radio transmitter, this futuristic design provides the highest viewpoint over the city. The top antenna reaches 288.4m (946 ft) and the top of the pod, which has thirteen floors, reaches 152m (499 ft).
The tenth floor of the pod is open to the public.
The tower has a hollow slip-formed, reinforced concrete main shaft of only 4.5 m diameter, which reduces to a mere 3 m to hold a radio mast which telescopes from 2.7 m to 0,7m. The thirteen floors are surrounded by a perimeter of open stainless steel grilles and suspended from the shaft by three primary vertical steel trusses.
The total weight of the tower is 3,000 tons.
A large amount of cables keep the tower upright: