 The Copán buildings suffered significantly from forces of nature in the centuries between the site's abandonment and the rediscovery of the ruins.After the abandonment of the city the Copán River gradually changed course, with a meander destroying the eastern portion of the acropolis (revealing in the process its archaeological stratigraphy in a large vertical cut) and apparently washing away various subsidiary architectural groups, including at least one courtyard and 10 buildings from Group 10L–2.The cut is an important archaeological feature at the site, with the natural erosion having created an enormous cross-section of the acropolis.