Nauen Transmitter Station
Nauen Transmitter Station (German: Grossfunkstelle Nauen or Sender Nauen) in Nauen, Havelland district, Brandenburg, Germany, is the oldest continuously operating radio transmitting installation in the world. Germany's first high power radio transmitter, it was founded on 1 April 1906 by Telefunken corporation and operated as a longwave radiotelegraphy station through World War II, and during World War I became Germany's main link with the outside world when its submarine communications cables were cut.
Source: Wikipedia — Nauen Transmitter Station (CC BY-SA 4.0)