Alte Burg, 'The old castle', in Burgsinn is a moated castle owned originally by the Barons of Thüngen. In 1337, the Bishop of Würzburg granted the castle and all its possessions as a fief to Dietz von Tungden, who largely built the present castle between 1339 and 1342.
The wide moat surrounding the castle is fed by an underground spring. On the west side, a bridge leads into the castle, which has a trapezoidal layout with towers at its corners. The outer wall is made of rusticated sandstone blocks, while the rest of the masonry is rubble stone, and the southern residential building features timber framing on its upper levels.
The square northeastern tower includes a small elevated residence. A pointed arch door leads into the southeastern tower, which was completed in 1543 by Martin I von Thüngen. The southern wall has been significantly altered with inserted windows, and the round-arched gate at the southwestern tower was fitted with corbels.
The castle complex is dominated by a square, five-story, 22-meter-high keep (dating to the 12th century), constructed of rusticated stones.
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.