The origins of Surenburg Castle are unknown, but it may be established as an estate of Münster bishop around 1400. The first document of castle dates from 1474. The moated castle is on two artificial islands. The oldest parts date from the late 16th century. The main building was built in the 18th century.
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.