Josef Oak, Ancient oak tree in Gmina Wiśniowa, Poland.

Josef Oak is a pedunculate oak growing in the historic park of the Wiśniowa manor estate in the Subcarpathian Voivodeship. The tree is about 650 years old, with a thick trunk and a crown of spreading branches. Its hollow interior is large enough for a person to step inside.

The tree was planted roughly 650 years ago and stands as one of the region's oldest natural monuments. During World War II, its hollow trunk provided shelter to a Jewish family fleeing persecution in the area.

The tree appears on Polish banknotes and represents the connection between nature and national identity in the country's symbolic imagery. Visitors come here to see the landmark that holds a special place in local and national consciousness.

The tree sits in an open area and is accessible via marked paths through Gmina Wiśniowa, though the terrain can be uneven. Visitors can explore the interior of the hollow trunk when conditions permit, though sturdy shoes and basic mobility are helpful.

The tree won the title of European Tree of the Year in 2017, marking the first Polish tree to receive this honor. This recognition brought international attention to the monument and strengthened its status as a symbol of natural heritage.