Corbera Castle is an impressive Muslim fortress, whose foundations lay on Roman remains. It has an irregular base, following the shape of the hill on which it rests. It was constructed in the 11th century to control the foothills of Murta and the coast. It is still possible to see the wall, the buttresses of the parade enclosure and the albarrana tower, which dates back to the Almohad period and it is one of the best-preserved towers in Europe. The complex was almost totally destroyed in 1521, during the Revolt of the Brotherhoods.
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.