What is the oldest tree in Thessaloniki?

In 2019, a University of Thessaloniki study identified four Oriental plane trees in the historic center old enough to merit protection as natural monuments, dated by core sample rather than by estimating from girth alone. The oldest by a wide margin is the Kastro Plane, at the corner of Acropoleos and Eptapyrgiou streets in Kastra, the old town below the Byzantine walls, core-sampled at approximately 828 years, more than twice the age of the other three (310, 235 and 205 years). Its size has barely changed across more than a century of photographs, read by researchers as the signature of a very old, slow-growing tree rather than a young one still filling out. It once grew beside a public fountain fed by the aqueduct of the nearby Vlatades Monastery, at what was then the boundary between an Ottoman Turkish neighbourhood and a Greek one; the fountain was demolished around 1940 during road widening, and the tree's vigour has reportedly declined somewhat since. All four trees stand outside the burn line of the catastrophic 1917 fire that destroyed roughly a third of the city center, part of why they survived to be dated at all.