That Hammer cost 3,500!https://www.jimbodetools.com/products/rare-fish-head-hammer-one-of-only-two-known-excelsior-92052
Carpentry. And I don't think it's that old. The shape is so similar to modern carpentry hammers, that I think it is not older than the standardised nail. Most definitely younger than the middle ages.
Fish Hamma