They look for areas where faulting or erosion have occurred, exposing surfaces that may give some clues to the point of finding fossils and artifacts. Sometimes they have to dig deep to find physical remains.
Identification or differentiation of the physical features of an area from those of the ground in places around. For example, a small part of an early settlement, such as a few stones in a regular pattern may be seen on the surface in such an area.
Enquiries on sites mentioned in a historical document or an oral narrative of the geography and other historical features of the area cited. This may lead to important insights to past civilizations, such as Troy, Ur, Babylon, Omo River valley and Olduvai Gorge.
Long experience in identifying a potential site for archaeological excavation.
Accidental exposure of ancient objects during cultivation and building construction, which could arouse the curiosity of researchers.