Hohensax is a ruined castle in the Sennwald. The castle was built around 1200 by the barons of Sax, and was destroyed in 1446. In 1248, the castle passed to Ulrich von Sax, founder of the Sax-Hohensax line of the noble family. The castle was plundered in a feud of 1393, and sold together with the villages of Sax and Gams to the dukes of Austria. In the Old Zürich War, the people of Appenzell captured and slighted the castle in 1446.
After this, the barons of Hohensax resided in the nearby Forstegg castle at Salez. In 1640, the ruin passed to the barony of Sax-Forstegg, one of the constituent parts of the canton of Linth of the Helvetic Republic in 1798, and later the canton of St. Gallen. It included the villages of Sax, Salez and Gams.
References:Celje Castle was once the largest fortification on Slovenian territory. The first fortified building on the site (a Romanesque palace) was built in the first half of the 13th century by the Counts of Heunburg from Carinthia on the stony outcrop on the western side of the ridge where the castle stands. It had five sides, or four plus the southern side, which was a natural defence. The first written records of the castle date back to between 1125 and 1137; it was probably built by Count Gunter. In the western section of the castle, there was a building with several floors. Remains of the walls of this palatium have survived. In the eastern section, there was an enclosed courtyard with large water reservoirs. The eastern wall, which protects the castle from its most exposed side, was around three metres thicker than the rest of the curtain wall. The wall was topped with a parapet and protected walkway.