Cobá was settled as early as 100 B.C. around a collection of small lagoons; it’s a logical and privileged location, as the Yucatán Peninsula is virtually devoid of rivers, lakes, or any other aboveground water.
Cobá developed into an important trading hub and in its early existence had a particularly close connection with the Petén of present-day Guatemala. That relationship would later fade as Cobá grew more intertwined with coastal cities like Tulum, but Petén influence is obvious in Cobá’s high steep structures, which are reminiscent of those in Tikal.
At its peak, around A.D. 600–800, Cobá was the largest urban center in the northern lowlands, with some 40,000 residents and over 6,000 structures spread over 50 square kilometers (31 square miles). The city controlled most of the northeastern portion of the Yucatán Peninsula during the same period before being toppled by the Itzás of Chichén Itzá following a protracted war in the mid-800s.
Following a widespread Maya collapse—of which the fall of Cobá was not the cause, though perhaps an early warning sign—the great city was all but abandoned, save as a pilgrimage and ceremonial site for the ascendant Itzás. It was briefly reinhabited in the 12th century, when a few new structures were added, but had been abandoned again, and covered in a blanket of vegetation, by the time of the Spanish conquest.
© Gary Chandler & Liza Prado from Moon Yucatán Peninsula, 9th edition