One of the most remarkable of the _chultuns_ found in this area is situated at San Andres, within a mile of the village of Corozal. It was accidentally found by some coolies in digging marl, and as, unfortunately, the entire roof of the larger chamber and a considerable part of that of the smaller had caved in, it was impossible to discover how it had been entered from outside, as no trace of steps remained. A ground plan of this _chultun_ is shown in figure 27. The small chamber, A, is 8 feet long, 7 feet broad, and 5 feet 6 inches high in the center; it is cut out of solid rock. The large chamber (C) is 15 feet in diameter, but as nearly the entire roof has fallen in, it is impossible to estimate its exact height. The chambers are partially separated by a wall (B) built of rough blocks of stone and tough mortar, which has been partly broken down. In the side of the small chamber, opposite the wall, are three oblong shafts (D, D, D, fig. 27) cut into the rock, by the side of the chamber wall, which is here nearly perpendicular. Each of these is about 1 foot in depth by 8 to 9 inches in breadth, and is separated from the chamber by a single row of bricks (E, E, E, fig. 27) mortared together, reaching from the roof to the floor, so that there is no communication between the shafts and the chamber. Each shaft opened originally on the surface of the ground, but the openings had become blocked by vegetable refuse from the surrounding bush. The bricks which fill in one side of each shaft are of two kinds. The first, by far the more numerous, are made of sun-dried clay, yellowish in color, and very friable: they contain considerable powdered marl. They measure 8 by 4 by 2-3/4 inches. The bricks of the second kind also are made of clay, mixed with many pebbles; they have been fired, are of a reddish color, far harder and tougher than the first variety; they measure 8 by 4 by 2-1/4 inches. Nothing was found in either chamber except a few potsherds of various kinds. [Illustration: FIG. 27.--Ground plan of chultun.]