The Sessile Oak of Belvedereallee

This sessile oak stands on Belvedereallee, a quieter stretch of the Prater than the chestnut-lined Hauptallee that gets all the postcards, in what is left of the floodplain forest that covered this ground before Emperor Ferdinand I ordered the first avenue cut through it in 1538. Vienna protected the tree as a natural monument in 2009, recording a trunk 4.5 metres round at chest height and a crown spreading close to 29 metres, big enough that Naturdenkmal Nr. 818 reads more like a description of a small wood than a single specimen. Nobody has published an age for it, and this pass has not guessed one: sessile oaks growing wild in a remnant floodplain forest do not follow the growth-rate tables a planted park tree does, so a girth-based estimate here would be a guess dressed as a number rather than the honest gap it actually is. It stands roughly 1.8 kilometres from the Hauptallee chestnuts, deep enough into the Prater that reaching it means committing to the park rather than passing through it: a 45-minute walk from Praterstern, or a shorter bus ride to the Freudenau or Lusthaus stops nearby. Free, open at all times, no ticket and no gate.