How long ago did you last explore your home? Any old structure is sure to have a complex history, with many secrets from its previous occupants. It has an ambiance– just one of the reasons some people choose to live in such places. And every now and then, these secrets come back and are revealed once again. We’ve gathered a selection of photographs taken by individuals during home remodeling projects when they unexpectedly discovered hidden gems. Renovating an old house is difficult, but with attention and caution, you might just uncover a piece of history. Here are 40 of the most unusual discoveries people made in their houses, from sealed vaults to vintage food packaging.

Fossil under the kitchen floorboards
Although it may seem strange, in 1987, Wyoming declared two state fish: the cutthroat trout and Knightia (Knightia eocaena), an ancient herring. The former is the state’s only existing native trout, while the latter’s fossils are scattered throughout the state.

A long-ago species of herring lived in a lake where southeastern Wyoming is now located. This group of fish was closely related to the Clupea herrings that lived around 50 million years ago. The only thing we know about what happened to them is that they suddenly died out.