Denmark 1942 – Round Tower observatory 

Copenhagen’s Round Tower Observatory (Rundetårn or Rundetaarn in Danish) is said to be the oldest still-functioning observatory in Europe. It was built in 1637–42 as a successor to Tycho Brahe’s private observatory Stjerneborg on the island of Hven, which had been demolished after his death in 1601. The Round Tower adjoins the University of Copenhagen’s Trinitatis Church, which lies behind it as drawn on the stamp. The observatory’s first director was Christian Longomontanus (1562–1647), a former assistant of Tycho Brahe. 

The tower ceased to be used for serious observations in the 19th century but still functions as a public observatory. In 1929 a more modern observatory with a dome was added on top of the original observation deck, which lies 35 metres above street level. 

This 10-øre stamp was issued in 1942 to mark the Tower’s 300th anniversary. A surcharged version in favour of the Red Cross was released in 1944 with a red overprint ‘+5’, as shown above right. 

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