una, dos, tres piedras. keach: here in honduras, a survey team combs the copan valley.ained eyes recognize mounds of grass-covered stones as the remnants of ancient maya dwellings. okay. there's the road. mm-hmm. this...here's where we came in -- a small road. and we walked around this way, and we walked over into this pasture. and so this site is right about here, right on this little hill. keach: the copan valley lies 100 kilometers north of ceren. in 1975, archaeologists began a complete survey of the valley on foot. after 10 years of painstaking work, they have discovered the remains of 4,500 structures. más a usted... cinco centímetros. keach: archaeologist william sanders has been leading excavations in the copan valley since 1980. sanders: we decided to do a series of large-scale excavations out in the countryside to get an idea what the farming population was like. what kind of houses did they live in ? what was their lifestyle like ? probably 80% of the population of copan was in that social category. keach: unlike ceren, the ancient houses of copan had been ex