The Horse Chestnut of Palacete Burmester

Every conker in Europe descends from a handful of mountain ravines in Greece and Albania, the only places the horse chestnut still grows wild, and where the species is now classed as vulnerable. Everywhere else it is a planted tree, and this is one of Porto's. It stands in the garden of the Palacete Burmester, the house the University of Porto runs as the Casa dos Livros on the Faculty of Sciences campus, and in 2020 it was classified a tree of public interest along with three neighbours on the same lawn: a Himalayan cedar, a tulip tree and a yew. Four protected trees in one small garden is somebody's collection rather than an accident. How old this one is, nobody has written down. Neither Portugal's forest register nor the city council gives it a date. The register holds a single measurement, a trunk 3.15 metres around in 2020, which on this species means well over a century and stops being useful after that. So the honest version is a tree that is protected, mature and undated, and anyone quoting a year for it is guessing. The garden sits a few hundred metres from the Jardim Botânico do Porto, close enough that its redwood, its bischofias and its cedars belong on the same afternoon.