A rotating hinge I thought was cool
https://pixelfed.social/p/Pixoremasune/575244476825082557Open linkView original on feddit.dehttps://pixelfed.social/p/Pixoremasune/575244476825082557Open linkView original on feddit.dehttps://pixelfed.social/p/Pixoremasune/575244476825082557Open linkView original on feddit.de
Cool! Might be wrong, but if i remember correctly, this type of hinge was made for use on an uneven surface.
It's a way to make a self-closing gate that uses gravity rather than a spring. Those two pivot points are each offset horizontally from the upper hinge.