Gerulata was a Roman military camp located near today's Rusovce, a borough of Bratislava. It was part of the Roman province Pannonia and built in the 2nd century as a part of the Limes Romanus system. It was abandoned in the 4th century, when Roman legions withdrew from Pannonia.
Today there is a museum, which is part of the Bratislava City Museum. The most preserved object is a quadrilateral building 30 metres long and 30 metres wide, with 2.4 metre thick walls.
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.