Buildings C, D and E - Radio Kootwijk

With the advent of shortwave technology in the mid-1920s, the older longwave technology soon became obsolete. Shortwave could cover long distances more efficiently thanks to its ability to reflect signals via the ionosphere.

Along the Turfbergweg, three transmitter buildings specifically for that shortwave technology were erected. They are known by the names: Building C, D and E. These buildings were equipped with shortwave transmitters, water-cooled transmission lamps (or transmission tubes) and associated cooling ponds. Building C facilitated connections with the Dutch East Indies; Building D with Suriname, the Antilles, North and South America, and some European countries; and Building E focused on Japan, with possibilities for expansion.

The broadcast buildings were built in 1929 in a business expressionist architectural style. In the 1950s, the cooling pond of Building E was put to use as a swimming pool with associated pool house cum changing room.