Take or find aerial photographs of the land being surveyed. Archaeologists consider photographs taken from low-altitude aircraft to be the best for survey purposes. Take either vertical photographs from directly over the site or oblique photographs from an angle.
Scrutinize the photos for clues to a historical site. Look for difference in soil color that could be caused by ancient construction. If the site contains buried ditches or walls, it will cause the soil to hold more or less water, which in turn causes variations in tones and color of vegetation, called crop marks.
Research local folklore to gather clues about old settlements in the area. Ask elderly longtime residents about places of archaeological interest. Oral tradition is a valuable source of information.
Check the local government office, university, library or archaeological office to find out if anyone previously excavated the site.
Review the information about the site to determine historical land use and environmental conditions in the geological past.
Walk over the area to investigate the survey site. Give special attention to signs of ruins and old artifacts and land features that suggest archaeological interest. Divide the map of the survey site into grids to ensure that you cover the entire site.
Dig a test pit to check if a given spot contains historical artifacts. Typically, test holes are 1 meter deep with length and breath equal to 25 to 100 cm.