Hajnáčka castle was built in the Gothic style against the Mongol invasion in the mid-1200s. Later, in the mid-15th century, the construction was finished. Hajnáčka was the seat of important feudal lords. In 1545 the castle was besieged and conquered by Ottomans. At the end of the 16th century and the first third of the 17th century castle was an important part of the anti-Turkish defensive line. Nevertheless, it Turks in 1645 again briefly occupied for few years. In the 17th century the castle was only partially inhabitated. In 1703 it was burnt down and no longer restored.
Today the remains of walls stand on the top of the hill which is hard to reach.
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.