When Mrs. Le Plongeon and myself landed at Progresso, in 1873, we thought that because we had read the works of Stephens, Waldeck, Norman, Fredeichstal; carefully examined the few photographic views made by Mr. Charnay of some of the monuments, we knew all about them. Alas! vain presumption! When in presence of the antique shrines and palaces of the Mayas, we soon saw how mistaken we had been; how little those writers had seen of the monuments they had pretended to describe: that the work of studying them systematically was not even begun; and that many years of close observation and patient labor would be necessary in order to dispel the mysteries which hang over them, and to discover the hidden meaning of their ornaments and inscriptions. To this difficult task we resolved to dedicate our time, and to concentrate our efforts to find a solution, if possible, to the enigma. We began our work by taking photographs of all the monuments in their _tout ensemble_, and in all their details, as much as practicable. Next, we surveyed them carefully; made accurate plans of them in order to be able to comprehend by the disposition of their different parts, for what possible use they were erected; taking, as a starting point, that the human mind and human inclinations and wants are the same in all times, in all countries, in all races when civilized and cultured. We next carefully examined what connection the ornaments bore to each other, and tried to understand the meaning of the designs. At first the maze of these designs seemed a very difficult riddle to solve. Yet, we believed that if a human intelligence had devised it, another human intelligence would certainly be able to unravel it. It was not, however, until we had nearly completed the tracing and study of the mural paintings, still extant in the funeral chamber of Chaacmol, or room built on the top of the eastern wall of the gymnasium at Chichen-Itza, at its southern end, that Stephens mistook for a shrine dedicated to the god of the players at ball, that a glimmer of light began to dawn upon us. In tracing the figure of Chaacmol in battle, I remarked that the shield worn by him had painted on it round green spots, and was exactly like the ornaments placed between tiger and tiger on the entablature of the same monument. I naturally concluded that the monument had been raised to the memory of the warrior bearing the shield; that the tigers represented his totem, and that _Chaacmol_ or _Balam_ maya[TN-2] words for spotted tiger or leopard, was his name. I then remembered that at about one hundred yards in the thicket from the edifice, in an easterly direction, a few days before, I had noticed the ruins of a remarkable mound of rather small dimensions. It was ornamented with slabs engraved with the images of spotted tigers, eating human hearts, forming magnificent bas-reliefs, conserving yet traces of the colors in which it was formerly painted. I repaired to the place.