The 15th century Château des Ducs was a massive castle in Alençon. The first castle, built in the 11th century, is completely disappeared today. The next castle was built by Peter II, the count of Alençon between 1361-1404. It was demolished 1592. Today only a impressive gatehouse and part of the walls remain.
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.