Podkraj is a village that stretches under the mighty plateaus of the high karst Nanos, Hrusica and Trnovo forest. The villages and hamlets of Visnja, Bela, Vodice, Trsevje and Hrusica also belong to the sub-district headquarters.
Hrusica, extending at an elevation of 858 meters above sea level, is best known for its Roman fortification Ad Pirum. At Hrusica there was a post office from the 1st century on, where it was possible to change the horse-drawn carriage, and from the 2nd century onwards there was also a guard post. In the second half of the 3rd century, the Romans built a fort or castle on Hrusica. Most of the finds date back to this time and mostly to the 4th century, which indicates a large settlement during this period. In the midst of increasingly dangerous barbaric incursions and battles between the armies of different imperial candidates, Hrusica had an important position because it protected the main road from the Balkans to Italy. It was probably a permanent military outpost here. Hrusica became part of the July Alpine defense system, which protected Italy when defense at the borders of the empire was no longer sufficient. The floor plan of the castle is adapted to the land and is in irregular oval shape. The castle was most probably abandoned around 400 AD. Traffic through Hrusica continued until the end of the 6th century. The pear is also mentioned in the famous work of Janez Vajkard Valvasor (1641-1693) - the Glory of the Duchy of Carniola.
At the Old Post inn, visitors can view an archaeological exhibition of objects that were excavated in the area of the former post office and, later, important Roman fortifications within the walls of the Claustra.