Fernsehturm Berlin

That silver sphere piercing the Berlin sky is the Fernsehturm, the Television Tower, and it has one of the most entertaining origin stories of any structure in Europe.

East Germany built it in the 1960s with a very deliberate message: socialism works, and we can prove it. Construction began in 1965, and when the tower opened in 1969, an entire historic neighbourhood called the Marienviertel had been demolished to make room. At 365 metres tall, one for every day of the year, the planners clearly loved a good symbol. A later antenna pushed it to 368 metres, making it the tallest structure in Germany.

The sphere itself was inspired by the Soviet Sputnik satellite, and assembling it piece by piece high in the air was a genuine engineering feat with limited East German resources. They were rightly proud of it.

Then the sun came out. On bright days, the metal panels on the sphere reflect light in the shape of a glowing cross. In a state that officially rejected religion, this was a spectacular problem. Berliners immediately nicknamed it "The Pope's Revenge" and "St. Walter," a jab at leader Walter Ulbricht. The government tried everything to remove it. The cross stayed.

After reunification, the tower shed its political baggage and became a symbol for all of Berlin. Over a million visitors come each year, mostly for the view, and partly, perhaps, to check if the sun is out.