Lamanai: Structure N9-56
"The construction sequence in N9-56 is now the most thoroughly explored among the larger structures at Lamanai, and it also extends over one of the longer spans of time. Underlying the late Early Classic construction...we encountered a well-preserved building that served as the primary structure for the modifications that followed...
The excellent preservation of the N9-56 primary structure is particularly fortunate, for it has left to us the large and unusual masks that adorn the stairside outsets. We have excavated only those at the south, but limited probing indicates that the northern masks exist in an equally good state of preservation."
Pendergast, Journal of Field Archaeology 8:1 37