This photo shows the late great Grigio the Cat (rest in peace, little grige) hanging her head in shame over the indoor-outdoor grotesquely stained carpet that covered the hallways when I first moved in, in 2002.
Gross!!! I lived with them for a few years, then with the help of friends (I have really, really good friends), pulled up the carpet and had professionals come in and sand and stain the floors.
Things found under the carpet: original linoleum (which decomposed upon being touched), keys, razor blades (?), and old newspapers from the 1930s (kept those).