The Ramsberg Castle was built around 1200-1225 probably by the knight Ulrich von Plochingen and Konrad, the monk from Rechenberg. In 1327-1529 the castle was owned by the lords of Rechenberg. The Gothic chapel was built in 1560. It was initially dedicated to St. Margaret and later to St. Martin. Between 1560 and 1580 the castle was rebuilt a second time.
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.