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 Church of Our Lady before Týn is a dominant feature of the Old Town of Prague and has been the main church of this part of the city since the 14th century. The church's towers are 80 m high and topped by four small spires.
In the 11th century, this area was occupied by a Romanesque church, which was built there for foreign merchants coming to the nearby Týn Courtyard. Later it was replaced by an early Gothic Church of Our Lady before Týn in 1256. Construction of the present church began in the 14th century in the late Gothic style under the influence of Matthias of Arras and later Peter Parler. By the beginning of the 15th century, construction was almost complete; only the towers, the gable and roof were missing. The church was controlled by Hussites for two centuries, including John of Rokycan, future archbishop of Prague, who became the church's vicar in 1427. The roof was completed in the 1450s, while the gable and northern tower were completed shortly thereafter during the reign of George of Poděbrady (1453–1471). His sculpture was placed on the gable, below a huge golden chalice, the symbol of the Hussites. The southern tower was not completed until 1511, under architect Matěj Rejsek.
After the lost Battle of White Mountain (1620) began the era of harsh recatholicisation (part of the Counter-Reformation). Consequently, the sculptures of 'heretic king' George of Poděbrady and the chalice were removed in 1626 and replaced by a sculpture of the Virgin Mary, with a giant halo made from by melting down the chalice. In 1679 the church was struck by lightning, and the subsequent fire heavily damaged the old vault, which was later replaced by a lower baroque vault.
Renovation works carried out in 1876–1895 were later reversed during extensive exterior renovation works in the years 1973–1995. Interior renovation is still in progress.
The northern portal is a wonderful example of Gothic sculpture from the Parler workshop, with a relief depicting the Crucifixion. The main entrance is located on the church's western face, through a narrow passage between the houses in front of the church.
The early baroque altarpiece has paintings by Karel Škréta from around 1649. The oldest pipe organ in Prague stands inside this church. The organ was built in 1673 by Heinrich Mundt and is one of the most representative 17th-century organs in Europe.