Posert Castle, also known as Šabec (Schabez) and St. Martin, is a ruined fortress near the road between Paz and Šušnjevica, in municipality of Cerovlje. The ruins of the castle depending on the name are dating back to the 11th century (St. Martin), or 16th century (Šabec), while by archeological evidence to the second half of the 14th century. The castle was vastly devastated in the Uskok War (1615–17). Between 2009 and 2014 the castle was restored. Nearby the castle there is also a small Church of St. Martin from 1367.
The castle is of irregular trapezoidal layout with rectangular angle tower. The layout broad side is faced toward north. It consists of center in the northern part, and of external fortified yard in the central and southern part. The guard tower is best preserved. It had five floors, preserved to a height of 17 metres with irregular layout, 8 metres long by 6 metres wide.
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.