The Vienna Donauturm (English: Danube Tower) was created in 1964 by architect Hannes Lintl in the course of the Viennese International Horticultural Show (WIG 64). Since then it has become a part of the Viennese skyline and has become a popular lookout point and a tourist attraction. It is situated in the middle of the Donaupark, which was built to host the horticultural fair in Vienna's 22nd District, Donaustadt, near the northern bank of the Danube. With a height of 252 meters, it is one of the tallest buildings in Vienna. 776 steps lead to its viewing platform, which is at a height of 150 meters. It can be reached by means of two elevators, which take visitors upwards in only 35 seconds. Two rotating restaurants (at a height of 160 and 170 meters) offer a varied view over the Austrian capital. It takes the platform either 26, 39 or 52 minutes per revolution.

Text Source: Wikipedia