 The only similar structure in the region which may date from this period is Structure V at Kohunlich (Andrews 1987), but even this is uncertain.The existence of these structures indicates that the origin of columned buildings may be a southern lowlands innovation which was incorporated into later northern lowlands architecture, rather than an indicator of Terminal Classic/Early Postclassic interaction, as some have argued.These two buildings define the east side of the Main Plaza at Blue Creek.