The Berlin Radio Tower or “Berliner Funkturm” is a well-known landmark in Berlin. A 146-meter-tall lattice tower, the tower has a restaurant at a height of 51.65 meters and an open-air observation deck at 121.49 meters.
There is a unique feature of the radio tower, which is that its feet stand on large porcelain insulators, insulating it from the ground. Towers standing on insulators are not uncommon on long- and medium-wave broadcasting sites, but these towers are not normally open for tourists, as they have high voltage, and are dangerous. The Berlin Tower, which was built between 1924 and 1926—and was always intended to be open to tourists—almost had the same problem. After it was completed, it was discovered that it would be nearly impossible to get tourists on the insulated tower without endangering them.
Eventually the broadcasting element of the tower was scrapped in favor of the tourists, and the Berlin Radio Tower was turned into merely a nice place to get a meal and look out over the city, which it still is today.
Update as of August 2023: The tower is closed until fall 2023.