Isenburg Castle was built by the Counts of Isenburg around 1100 if not prior. Occupied by several branches of the Isenburg family, it was inhabited into the early 17th century. Shortly after being abandoned, it became a ruin. After the branch of Lower Isenburg had extinguished in 1664 with count Ernst of Isenburg-Grenzau, the county was partitioned between the counts of Walderdorff and the counts of Wied-Neuwied. The present owner of the castle is Maximilian, 9th Prince of Wied, son of Carl, 8th Prince of Wied and Princess Isabelle of Isenburg.
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.