Ojstrica Castle (Slovene: Grad Ojstrica, German: Osterwitz, Osterwiz, Osterbitz) was a castle above the settlement of Loke in the Municipality of Tabor in central Slovenia. Today only a ruin remains of the castle on a hill locally known as Stari Grad (Old Castle) southwest of the settlement core. It was originally built in the 13th century and belonged to the Counts of Celje. It was abandoned in the 16th century after it was attacked during a peasant revolt in 1535. By the early 17th century it was already a ruin. Today all that remains are parts of the fortifications.
- Slovenian Ministry of Culture register of national heritage Archived July 12, 2010, at the Wayback Machine reference number ešd 10401
- Slovenski biografski leksikon Archived 2009-12-19 at the Wayback Machine. Dictionary of Slovene Biography, published by the Research Centre of the Slovenian Academy of Sciences and Arts
- Media related to Ojstrica Castle at Wikimedia Commons