There is an underground chamber beneath one of the temples, built in the shape of a cross with each arm about twelve feet long. The sides are worked into the same mosaic pattern as the rest of the walls. It is generally believed that these chambers were tombs, although some contend that they were the entrance to subterranean passages leading long distances away. If so, the passages were filled up long ago. The northwestern group is in the best state of preservation. One of the buildings here covers nearly eight thousand square feet, and has all its massive walls intact with scarcely a stone thrown down. The characteristic entrance, consisting of three doors, side by side, is seen here also, fronting the interior of the court. The lintels are immense blocks of stone eighteen feet long, five feet wide and four feet high. How these immense stones were transported to this spot and raised without the aid of machinery, is as great a mystery as similar accomplishments by the Egyptians. Through these doors the famous Hall of Monoliths, or Columns, is reached. This is a wonderful relic of prehistoric architecture. The six monolithic columns, still standing in this room are each twelve feet in height and almost nine feet in circumference. They are plain stones having neither pedestal nor capital and are unique among the ruins of the world. Torquemada, an old Spanish historian, writes of this hall in the following quaint style: “There was in those Edifices, or Square of the Temple, another Hall, all framed around Pillars of Stone; very high and so thick that scarce might two Men of good height embrace them so as to touch finger tips the one with the other. And these Pillars were all of one piece; and they say that all the Pillars and Columns, from top to bottom, was four Fathoms. The Pillars were very like to those of St. Mary, the Greater, of Rome, all very well and smoothly wrought.” This hall is more than a hundred feet long, and twenty feet wide. These great stones may have supported a roof formerly but there is no evidence of it at the present time.