The Grimeton VLF transmitter in Vargerg is a VLF transmission facility, which has the only workable machine transmitter in the world. It has been declared a UNESCO World Heritage Site. The transmitter was built in 1922 to 1924; to operate at 17.2 kHz, although it is designed for frequencies around 40 kHz. The radiating element is a wire aerial hung on six 127-metre high freestanding steel pylons, that are grounded.
The Grimeton VLF transmitter location is also used for shortwave transmissions, FM and TV broadcasting. For this purpose, a 260 metre high guyed steel framework mast was built in 1966 next to the building containing the 40 kHz transmitter.
In 1945 the Grimeton VLF transmitter's twin station Nadawcza Radiostacja Transatlantycka Babice in Babice, Poland was destroyed. Until the 1950s, the Grimeton VLF transmitter was used for transatlantic radio telegraphy to Radio Central in Long Island, New York, USA. From the 1960s until 1996 it transmitted orders to submarines in the Swedish Navy.
In 1968 a second transmitter was installed which uses the same aerial as the machine transmitter but with transistor and tube technology. The machine transmitter become obsolete in 1996 and went out of service. However, because it was still in good condition it was declared a national monument and can be visited during the summer.References:
The Walhalla is a hall of fame that honors laudable and distinguished people in German history. The hall is a neo-classical building above the Danube River. The Walhalla is named for the Valhalla of Norse mythology. It was conceived in 1807 by Crown Prince Ludwig in order to support the then-gathering momentum for the unification of the many German states. Following his accession to the throne of Bavaria, construction took place between 1830 and 1842 under the supervision of the architect Leo von Klenze.
The memorial displays some 65 plaques and 130 busts covering 2,000 years of history, beginning with Arminius, victor at the Battle of the Teutoburg Forest in 9 AD.