This is the oldest house in the US. It's located just off the Old Santa Fe Trail in downtown Santa Fe, New Mexico, across from the oldest continuously occupied church in the US and just down the street from the oldest public building in the US. The house was originally built around 1610, but because it's made of adobe it has required significant maintenance over the years. Oddly, photographs from the 1880's and late 1920's show the house with two stories, but photos from 1912 only show one. In each of these photos the sand/clay/straw/dung walls are shaped differently, sometimes uneven and cracked, sometimes smooth and clean. The house is built on top of an ancient pueblo that dates to around 1200.