Sveti Juraj fortress near Nova Vas

Sveti Juraj fortress, also known as Santi Quaranta, is a protected cultural monument in the municipality of Brtonigla, located above the Mirna river valley near Nova Vas. The fortress is divided into a northern and southern part by an interior wall. Today, its trapezoidal floor plan and well-maintained walls are still visible. The northern plateau was once the centre of a Mediaeval town, and today it features an archaeological site with the ruins of the Church of St George.

Sveti Juraj fortress was built on a strategic position above the mouth of the river Mirna and its harbour. There may have been a prehistoric fortification and ancient settlement in the same place, followed by an ancient and early-Mediaeval fortified military camp. According to some sources, goods were delivered to Pišine harbour on the river Mirna until 1906, after which the pier was blocked with silt. A fire was lit on one of the fortress towers to help keep sailors on a safe course towards the harbour.

Historical sources note that the fortress belonged to Alderus de Castro S. Giorgii in 992AD, and it is known that it also belonged to Vidotto and Flabiano in 1230.

The patriarch of Aquileia purchased three-fourths of the property from America qm. Vidotti and the remaining fourth from Biachini, son of the late Ossalco di Momiano. He then renovated and expanded the fortress to create a new stronghold from which to guard his estate in Istria.

After the Venetians attacked in 1291 and the Genoese in 1354, the fortress lost its important political and military role, and began to pass from owner to owner. After 1420, the Venetian Republic gave it to Grožnjan.