These towers (pl. 23, _a_, _b_) show some of the finest masonry known
in this region, being constructed on fallen bowlders which their
foundations almost completely cover. Holly Tower (pl. 23, _b_) measures
16 feet high and 21 feet in diameter. It is 7 feet wide, its top rising
to a height level with that of the mesa on which stand buildings
already considered. One of the two rooms of this tower is narrower
and wider than the other, shown in an offset as if constructed at a
different time. Its foundations are 17 feet long by 8 feet wide, the
highest wall measuring, at the southeast corner, 12 feet 8 inches.
There is a fine doorway, wide above and narrow below, in the north
wall. The approach at present is difficult on account of the height
of the rock on which it stands, but there are evidences of former
footholes.