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:The Broch of Gurness is an Iron Age broch village. Settlement here began sometime between 500 and 200 BC. At the centre of the settlement is a stone tower or broch, which once probably reached a height of around 10 metres. Its interior is divided into sections by upright slabs. The tower features two skins of drystone walls, with stone-floored galleries in between. These are accessed by steps. Stone ledges suggest that there was once an upper storey with a timber floor. The roof would have been thatched, surrounded by a wall walk linked by stairs to the ground floor. The broch features two hearths and a subterranean stone cistern with steps leading down into it. It is thought to have some religious significance, relating to an Iron Age cult of the underground.
The remains of the central tower are up to 3.6 metres high, and the stone walls are up to 4.1 metres thick.