I'm not sure if this has been discussed in Hamsterdam yet, or at what length, but I'm fascinated by the tree shaping accomplished by a small collection of artists, who appear to all be strange hermits. The most famous early tree shaping was by Axel Erlandson, who in the 1920s started doing insane shaping of living trees that had never before been seen:
Axel never discussed his methods and seemed to do it really only to amuse himself, but he inspired others to create their own.
Everybody's favorite now has to be Pooktre, a team of Peter Cook and Becky Northey who have been making strange creations on their farm in Australia for the last couple decades. Click here for a GIS of Pooktre pictures that will blow your mind, I'll post a few here as well:
And for fun, some old-school tree shaping of roots to create root bridges in India:
To Hamsterdam, Y'all. Standard rules apply. Have a great Memorial Day.