I am actually looking at a house that's been on the market for ages, and I think I know why. It has uneven floors in the extreme. Walking through some rooms is like a taking a half step down that you didn't realize was there (in the middle of the room, not upon entry.)

The house is a genuine slice of history and I adore it, but fear this floor. Can it be fixed? How much would it cost? The house is no less than 359 years old, and has historical features that historians of the area say are only written about. But this floor!

It's not far from the coast. It is said that there was a time (way back when it was young) when dunes met this house. So I am thinking with sand moving around for 300 years the foundation has sunk. One the second visit to the house I realized that the floors sink away from the central fireplace. So I wonder if jacking it up to meet the fireplace would work, but at what cost both monetarily and in damage to walls, windows etc.