The 600-year-old castle linden tree is an impressive tree that stands at the entrance to the Schaunburg castle ruins in Upper Austria. It is a summer linden tree (Tilia platyphyllos) and has a trunk circumference of around 6.85 m. It was planted around 1402 and is therefore around 621 years old. It is a witness to the history of Schaunburg Castle, which was once the largest castle complex in Upper Austria and the seat of the Counts of Schaunberg. The castle was built in the 12th century and was the scene of the Schaunberg feud, which the Schaunbergers waged against the Habsburgs and the Wallseers. The castle fell into disrepair after the Schaunbergers died out in the 16th century and was partially demolished. The ruins are now a popular destination for hikers and cyclists, who can enjoy the wonderful view over the Eferdinger Basin. The castle linden tree is a natural monument and a symbol of the region's past and present.