What is the oldest tree in Athens?
Most likely the Olive Tree of Pisistratus, a protected olive in a small park in Agioi Anargyroi, a western Athens suburb, traditionally dated to more than 2,500 years by a 1919 Hellenic Archaeological Society survey. Modern dendrochronology of comparably old Mediterranean olives has repeatedly found real ages closer to three or four centuries once tested with radiocarbon methods, a test this specific tree has never had, so its true age is unverified rather than settled.
Olive trunks complicate every claim like this: the wood rots hollow from the centre as the tree ages, taking the earliest growth rings with it, so there is no ring count to check the Pisistratus olive's 2,500-year figure against, only the archaeological society's own 1919 measurement methods. Recent radiocarbon studies of other Mediterranean olives with similarly dramatic folk ages have generally found true ages in the low hundreds rather than the thousands, which is why this page states the claim without adopting it. What isn't disputed is the tree's resilience: part of its trunk was cut for firewood during the wartime occupation of the 1940s, and it grew back anyway, a protected natural monument since. Athens' more famous old tree, the mythologised olive beside the Acropolis's Erechtheion, loses on raw age despite the bigger story: the physical wood standing there today was replanted sometime in the early to mid 20th century after wartime damage, younger than the suburb's contender by a wide margin whichever date is used. The Pisistratus olive is free to visit, in a small park behind the church of Agioi Anargyroi, a short walk from Agioi Anargyroi railway station.
The yew, the oaks and their peers across other cities are collected in Europe's 10 Most Remarkable Ancient Trees.