Castle Wild (Wildburg) lies southern behind the Castle Treis. It was built in the 13th or 14th century, probably as protection of the southern side of the castle Treis. In the fifties it was restored and made fit to live in. Back then, the northern situated, almost square, donjon was repaired and received a new roof. The great hall and other outbuildings were also rebuilt. Other buildings and the circular wall are just ruins. Wildburg is private property so you can visit it only from the outside.
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.