Havránok is an important archaeological site in northern Slovakia. It is on a hill above the Liptovská Mara water reservoir around 2 km (1.2 mi) from the village of Bobrovník, about halfway between Ružomberok and Liptovský Mikuláš in the Liptov region. The archaeologists unearthed a prehistoric Celtic hill fort and a medieval wooden castle in the 1960s, during the construction of the Liptovská Mara dam. Both objects have been partially reconstructed. During the Iron Age and the Roman Era, the shrine of Havránok was an important religious center of the Celts living in Slovakia.