The Tammesalu Oak

Tallinn's thickest tree was already sizeable when Peter the Great bought the land it stands on. In 1714 the tsar acquired a small coastal manor and its oak grove, then built Kadriorg Palace beside them; a dendrologist who surveyed the grove in 2017 said the oak already had real girth then, meaning it predates both palace and park. The grove survived because someone kept managing it. For centuries, branches were cut back and young oaks planted in among the old ones to hold a tight canopy, which pushed this one to grow tall and straight rather than spreading wide the way a lone oak does. Landscape architect Georg Kuphaldt folded what was left into Kadriorg Park's naturalistic section from 1897, and the grove, Tammesalu, has outlasted the estate's changes of use since: a private manor, briefly Estonia's presidential grounds, now open parkland. Two measurements eight years apart agree closely: 637 centimetres round in 2016, 648 in 2024, the kind of slow thickening a tree this old shows rather than one still putting on growth. Kadriorg Park's own site names the same grove as home to its thickest oak. A different tree, a horse chestnut elsewhere in the city, tops Estonia's official monument register, because that one carries its own individual listing and this oak sits inside a protected grove instead. Nobody has pinned the exact trunk to a coordinate yet. It stands somewhere in the grove's northeastern corner, by Kirdetiik pond.