While there's always more to say on the subject, you might be interested in some previous answers here:
I live in a European city where they have found lots of old houses from the 14th century burried in the city center. At what point are those houses 1/2 burried and how do people just forget that the buildings used to exist in a location that has been constantly populated since they were built? by u/sunagainstgold
Where does the ground that cover the ruins of ancient building is from? by u/kookingpot