Seen here is the famous Tamme-Lauri oak, the thickest and oldest tree in Estonia, located in Urvaste Parish, Võru County. The height of the tree is 17 metres (56 ft) with a circumference of 831 centimetres (327 in). According to researchers the tree was planted around 1326. [source]

Tamme-Lauri oak is depicted on the back side of the Estonian ten kroon banknote and the land where the tree is located was bought by the Estonian Ministry of the Environment in 2006. The oak has been under protection since 1939. [source]

The oak has been hit repeatedly by lighting, damaging the branches, and the center has become empty as a result of the multiple strikes. Before the center cavity was filled with 8 tonnes (18,000 lb) of reinforced concrete, seven people could stand inside the cavity. [source]

This photo was taken last September and was a finalist for the 2013 Wikimedia Commons Picture of the Year.