The first historical mention of Gavnø is in King Valdemar's census book from 1231 where a 'house on Gavnø' is mentioned. The house was apparently a castle built to defend Denmark's western coasts. In the 15th century, Queen Margaret I opened St Agnes' Priory there, catering for nuns from aristocratic families. The chapel can still be seen in the castle's southern wing although it has since been extended.
In 1737, Count Otto Thott acquired Gavnø. He renovated and substantially extended the castle, creating today's three-winged, yellow-facaded building in the Rococo style where he was able to house his large collections of paintings, manuscripts and books. At his death, his library collection contained over 120,000 volumes, exceeding that of the Danish National Library. The park surrounding the castle is known for its rare trees, rose garden and, above all, its extensive display of bulbs.
References:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.