Cl PA 2003 XIX 11 ' International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
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Figure 3. Patrimonial buildings and topographic prominences in downtown area Mexico City. There is a 
clear relationship among cataloged buildings and the marks of the mounds produced by archaeological 
remains. 
concentration of recorded prominences. On most streets there 
are major topographic knolls indicating the presence of big 
structures. However, out of the old islet’s boundaries, there are 
little topographic mounds on record, which suggests precisely 
that the knolls constitute structures built within the territory of 
the main islet. 
The concentration of knolls proves the existence of pre-Hispanic 
settlements. Nonetheless, the classification of the mounds, 
alongside the geophysical results, allows for identifying a 
settlement’s main structures. The second phase of the project is 
now under way to study, using geophysical techniques, the 
features of the located knolls. This part of the research project 
resorts to topographic, magnetic, electric and radar equipment 
determining the presence and the characteristics of the building 
remains. Excavations and sounding drills constitute other study 
techniques so to confirm hypothesis posited from the results of 
the earlier stages. 
At the Coyoacan zone experiments were carried out to prove 
that geophysical high-resolution techniques are adequate to the 
task of studying archaeological sites in urban contexts. 
Topographic maps were made to carefully record the zone’s relief. 
Over the surface of the Conchita square a magnetic gradient study 
was undertaken which was able to overcome the interference 
produced by the urban infrastructure. There is good concordance 
between magnetic data and topographic knolls. A technique that 
has given good results has been electrostatic resistance, which 
without galvanic contact with the earth enables to obtain readings 
on the pavement. This eased the study of most streets surrounding 
the square producing a close correspondence between 
topographic mounds and high electrostatic resistance values. 
Preliminary results state that most mounds recorded are produced 
by materials that modify the magnetic and electric properties of 
the soil, also generating clear reflections of radar electromagnetic 
waves. Georadar has discovered the approximate depth and shape 
of accumulated collapsed materials that generate clear reflections 
and affirm doubtless the existence of buried architectonic 
remains.