Dicke Marie is an old oak near the shore of Tegeler See, traditionally dated to the late twelfth century. The name means "Fat Mary" and is said to have come from the Humboldt brothers, who associated the tree with a family cook. It is not a grand attraction, but it is a pleasant, odd Berlin detail if you are already walking around Tegel.
Dicke Marie
Ancient oak near Tegel, often described as the oldest tree in Berlin