Libušín, Cultural monument and hillfort in Kladno District, Czech Republic.

Libušín is an early medieval hillfort one kilometre south-west of the town of Libušín, five kilometres north-west of Kladno, at about 400 metres above sea level. Its four-part layout covers 12.3 hectares on a spur between the Svatojiřský and Libušínský stream gorges, with earthen ramparts up to 4.8 metres high and the Church of Saint George.

Archaeological research dates the hillfort's foundation to the second third of the 10th century, at the earliest under Duke Boleslaus I, not the end of the 9th century. During a short period of occupation the entrance from the outer bailey to the acropolis was closed, shrinking the site, and the fortification probably disappeared by the second third of the 11th century.

Chronicler Kosmas in the 12th century linked the hillfort to the mythical princess Libuše, saying she ruled from it, foretold Prague's future glory there and was buried on the site. Archaeology shows that in the 6th–7th centuries, when the legend is set, only an unfortified settlement stood here. The Church of Saint George stands within the hillfort area.

The site is best visited on foot, and sturdy shoes are a good idea given the uneven and hilly ground. Visiting in the warmer months gives you better conditions to walk around and sometimes coincides with local events.

The northern edge of the hillfort was disturbed in the 20th century by the Schöller coal mine, whose spoil heaps almost levelled the terrain there. The site's steep slopes once rose up to 60 metres above the surrounding valleys.