Münchhausen Castle was mentioned already in 893 AD when it was owned by the Abbey of Prüm in Lorraine. Later the castle was used as a customs office. The 12th and 13th century walls, tower and some buildings have survived. Today the castle is a horse farm with restaurant.
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.