For man made things, New Grange in Ireland. Predates the pyramids by a couple thousand years. Fascinating that the entrance still lines up with the sunrise on the winter solstice, and at no other time. Lots of theories about what it was for, but not sure if anyone living really knows.
As far as the oldest building goes, probably the historische wurstkuche in Regensburg. It’s been open as a restaurant since 1146 or so.
Old70
I believe the Hill of Tara, not far from there, is much older. One mass burial monument (The Hill of Hostages) was dated to 3200BC. Reigning kings lived there through at least 142 administrations. some pretty weird vibes catch a lot of people there.
