Complex sentence: It consisted of two rectangular rooms of unequal size, and appears to be intact in a 1586 map, but is shown as ruins in later charts; only the foundations and part of a wall still remain.
Split into simpler sentences: It consisted of two rectangular rooms of unequal size, and appears to be intact in a 1586 map, but is shown as ruins in later charts. Only the foundations and part of a wall still remain.