Complex sentence: The monument also contain ruins identified as a ball court, similar to the courts found in Meso-America and in the Hohokam ruins of southern Arizona; this is the northernmost example of this kind of structure.
Split into simpler sentences: The monument also contain ruins identified as a ball court, similar to the courts found in Meso-America and in the Hohokam ruins of southern Arizona. This is the northernmost example of this kind of structure.