Veisiejai manor park ash is a botanical natural heritage object of exceptional age and dimensions, growing in Lazdijai district, Veisiejai, in the southern part of the manor park, on the shore of Lake Ančia. It is the second thickest ash in Lithuania. The volume of the ash trunk is 5.4 m, the height is 31 m. The tree was planted more than 200 years ago. The park surrounding the ash was built in the 18th century by the Masalskis dukes, who ruled Veisiejai at the time and built the manor house.