Cobá Part 7: The great Ixmoja pyramid of Grupo Nohoch Mul

The Ixmoja pyramid is the tallest Maya structure in northern Yucatan. The height of the structure is 40m (131.2ft). In addition, Ixmoja stands on a small rise of about 6m (19.6ft), which gives it an extra bit of altitude. The tiny figures of tourists that you can see on the main staircase provide a sense of scale. Ixmoja is part of the Grupo Nohoch Mul, which includes several other structures. Built in stages during the Late Classic and Early Post Classic eras, Ixmoja was lost in the jungle for a thousand years until archeologists visited Cobá in the 19th century. 

In this posting, I'll show you the pyramid and tell you about an important discovery in 2024. Near Ixmoja, an archeologist stumbled--almost literally--across the Foundation Rock, a huge stone covered with hieroglyphs. While they have not been completely deciphered, some of the glyphs yielded fascinating new information about Cobá's Classic-era dynasty. They revealed a previously unknown female monarch named Ix Ch'ak Ch'een. She was  very powerful and established Cobá as a major player in the Maya world. (Photo from Travel Wonders)

Overview

Site map showing Grupo Nohoch Mul and the Ixmoja pyramid. The Nohoch Mul group is in the upper right. The pyramid is at the end of the purple trail and is marked Nohoch Mul, which means "Big Mound". Although the Ixmoja pyramid is sometimes called by that name, Nohoch Mul is actually the name for a whole group of structures. 

In addition to Ixmoja, the group includes a huge platform northeast of the pyramid called C-7. The platform is 17m (56ft) high, 125m (410ft) wide, and 115m (377ft) deep. When we visited, the platform was obscured by the thick jungle, so I didn't photograph it or even know it was there. West of the pyramid are Structures 10 and 12, supporting Stelae 20 and 21, respectively. These structures and their stelae were covered in Part 6.

The Foundation Rock. This large stone plaque was discovered inadvertently in November of 2024 by archeologist Ana Calderón while she was touring Grupo Nochoh Mul. The Foundation Rock is located about 152m (500ft) behind the Ixmoja pyramid, under a stairwell and beside a natural waterhole. While walking by, Calderón noticed a large stone that was literally covered with hieroglyphs, many of which seemed readable. This last was very important. Although Cobá probably has more hieroglyphs than any other site in Yucatan, they were carved into limestone of poor quality and have mostly become indecipherable. 

The stone monument measures 4.2m x 3.4m (14ft x 11ft) and contains 123 glyphs. Archeologists named it the Foundation Rock because it is, in effect, the founding document of a powerful, Early Classic era dynasty in northeast Yucatan. The dynasty had originally been established at Cobá in 494 AD by a ruler named Juunpiktook. He had gained his throne with the aid of the Kaan (Snake) Dynasty, a foreign power based in Dzibanche in southern Yucatan. Because of this, Cobá at first functioned as a vassal of the Kaan and the authority Juunpiktook and his early successors didn't extend much beyond the city itself. 

The only known image of Ix Ch'ak Ch'een appears on Stela 26. The stela is located in Grupo D and her name is mentioned in its glyphs. Ix is a female prefix, roughly meaning "Lady". Ch'ak Ch'een means "Red Rainbow". The image on Stela 26 differs from most of the others at Cobá. The figure faces left, rather than right, doesn't hold the long scepter of office, and has no captives at its feet. The sex of the image was determined by the ankle-length huipil (dress), a garment that Maya men never wore. Ix Ch'ak Ch'een was the first woman to rule Cobá, not as the consort of a male ruler but as a monarch in her own right.

She became Cobá's queen on an unknown date in the middle of the 6th century AD, about 60 years after Juunpiktook took the throne. There were probably 2-3 successors between his death and when she became the ruler. However, their names and the dates of their rule are uncertain. What the Foundation Rock tells us is that Ix Ch'ak Ch'een became Cobá's first Kaloomté in 569 AD. Kaloomté  ("Supreme Warrior") was the Maya world's highest rank. It was reserved for rulers of a whole region, not just a city. So, Ix Ch'ak Ch'een was both the first female ruler of Cobá and later became the city's first kaloomté. 

The pyramid's west and east sides 

View of the west side of the Ixmoja pyramid. Beside the main staircase stands a smaller one, with a palapa-covered stela at its base. The stela was created during the Classic era, but was moved from elsewhere in Cobá and re-erected here during the Post Classic. No clear images, glyphs, or dates are visible on the stela's broken pieces. 

There are at least 17 steps on the west-side staircase and the first four are broader than the rest. This fact, along with the sheered-off appearance of the staircase's west side suggest a collapse at some time in the past. At the top of this staircase are the remains of a small temple and another Stela 30.

One of the documented accomplishments of Ix Ch'ak Ch'een was the construction of Ball Court 2 in Grupo D. The significance of this is hard to overstate, because the ball game was central to Maya religious, political, and social life. Hieroglyphic inscriptions on the ball court's Panel 7 state that she dedicated the court in 573 AD. Another woman, Ix Che'enal, became kaloomté in 573, so Ix Ch'a Ch'een must have died sometime that same year.

A small ruined temple occupies a platform at the top of the west-side staircase. This photo was taken from the main staircase. The temple is a single room once covered by a vaulted stone roof. The entrance was between the two pillars. Stela 30 rests against the wall at the rear of the temple and is protected by a small palapa. The stela is broken and the side facing out shows the lower part of a standing figure. The side facing the wall contains the surviving glyphs, one of which contains the name Ix Ch'ak Ch'een Yopaat. This is one of several variations of this powerful queen's name that are found on different monuments.

Several artifacts were found in and around this temple. These included stone trays called metates, used for grinding maiz. Also present were charred bone fragments from deer and wild boar called jabali. These items indicate that the temple was used for ceremonial activity related to fertility because Maya codices (hieroglyphs on paper) show fertility offerings of venison on metates. Found under the floor, near the base of Stela 30, were beads of jade, coral, and shell pectorals. Ceramic fragments within the temple were from the Puuc area (northwest Yucatan). This indicates they were left during the Post Classic period. 

The east side of Ixmoja also contains structures, but in a more ruined condition. At the base, a three-step staircase leads up to a temple with a single room. It once had a vaulted roof, supported by two pillars. Along the rear wall of the temple is a long bench. Similar to the temple on the west side, ceramic fragments of offerings from the Puuc region were found. These included a slate-ware plate fragment containing the date 810 AD. This is one of the latest dates ever found at Cobá. It places the offering during the transition between the Late Classic and the Early Post Classic periods.

Ancient Maya rulers gained legitimacy not just with military power, but through their association with the gods. The glyphic inscriptions on the Foundation Rock closely connect Ix Ch'ak Ch'een with the deities who protected Cobá. One variation of her name includes the title K'awiil. This was a deity related to lightning, the serpent witz (associated with water), and royal lineage. The Foundation Rock's glyphs also connect her with Bolon Tz'akab Ajaw ("Lord of Innumerable Generations"). One of the key roles of a Maya monarch was to act as an intermediary between the gods and the people.

 The Main Staircase

The main staircase rises steeply. without landings. It is daunting enough to climb this seemingly unending set of stairs, but the return is especially precarious. Some people choose to come down on their butts, while clinging to a rope. I'm not particularly afraid of heights, but this staircase is in a class of its own. In 2019, the staircase was closed to tourists and in 2021 work was begun on a wooden staircase constructed up the middle. Finally, in 2025, the new staircase was opened to the public. I suppose it was necessary for safety, but I'm glad I got to climb Ixmoja the old fashioned way.

Like many other temples and pyramids throughout Mesoamerica, Ixmoja was built in stages. In 2016 archeologists discovered an earlier pyramid inside it that is about 10m (32.8ft) tall. They were able to detect this earlier structure with a non-invasive technology called tri-dimensional electric resistivity tomography. This, along with other new technologies, have revolutionized archeology. One of these, called Lidar (Light Detection and Ranging), can quickly scan huge areas of jungle from the air, revealing otherwise invisible structures. At Cobá, Lidar has been used to detect structures along the sacbeob.

Nearing the top, some people scramble up while others sidestep or crawl down. The first mention of Cobá' was made in a mid-19th century report by John Stephens and Frederick Catherwood. They heard about the city but couldn't reach it because of its remoteness. The first non-Maya to actually visit was Juan Peón Contreras Elizalde, director of the Yucatan Museum. He made the arduous journey through the jungle in 1882. Nine years later, in 1891, an Austrian explorer named Teobert Maler stopped for two days, but left quickly because of the Caste War. Thirty-five years passed before an American, Thomas Gann, visited in 1926. 

Gann's visit triggered a series of eight expeditions by the Carnegie Institution of Washington (CIW). Between 1926 and 1932, the CIW thoroughly explored and mapped the site. Over the next 40 years, other archeologists briefly stopped and reported their observations about the sacbeob and stelae they found. In 1972, the Mexican Instituto Nacional de Antropologia y Historia (INAH) began an intensive program of investigation and restoration. During this same period, the first modern road was built to the site. Even 144 years after the first visit, new discoveries continue to be made, the most recent being the Foundation Rock in 2024.

Temple of the Diving God

The Temple of the Diving God stands on the platform at the top of Ixmoja. The temple bears a strong resemblance to temples at Tulum and other Caribbean coastal sites of the Post Classic era. There is one room, entered through a single door. Unfortunately a barrier prevented me from accessing the interior. There were originally three niches across the top level, but the one on the far left appears to have broken off with a section of the roof. Each of the remaining niches contains a stucco statue of Ah Muzen Cab, a deity that archeologists call the Diving (or Descending) God because of how he is always portrayed. 

In addition to building Ball Court 2, Ix Ch'ak Ch'een was also responsible for construction of some of Cobá's 50+ sacbeob ("White Roads"). These not only tied the disparate parts of the city into a coherent whole, but they also connected Cobá with outlying areas. This road network was crucial in the development of the city as an economic, political, and military powerhouse. It was the extension of her power over a whole region that allowed Ix Ch'ak Ch'een to become the first of Cobá's rulers to achieve the title of kaloomté.

Ah Muzen Cab is always shown in an upside-down posture. His head is at the bottom and his legs and feet point upward. The stucco is too worn to see much of his arms. A similar statue occupies the other niche. This depiction led archeologists to dub him the "Diving God". Ah Muzen Cab is the protector of bees and beekeepers. One of Cobá's specialties was the production of honey for domestic use and for export. Hives of the Melipona becheii and Melipona yucatanica species of stingless bees were kept for these purposes. Ah Muzen Cab was revered, not only at Cobá, but also at Tulum and the other coastal cities. 

By becoming the kaloomté, Cobá's first female ruler elevated herself from the role of vassal or subordinate ally. This gave her greater importance in the eyes the rulers of other powerful cities like Calakmul and Tikal. During the Classic era, their military and political resources probably still exceeded that of Cobá. However, Ix Ch'ak Ch'een had established herself and her dynastic successors as a force that had to be reckoned with. The Foundation Rock also mentions an important, but undefined, relationship between her and Sky Witness, the powerful ruler of Dzibanche who decisively defeated Tikal in 562 AD.

The perilous climb down

Visitors to the top of Ixmoja gingerly pick their way down. I stood on the platform for a while, both to enjoy the view and to steel myself for the climb down. Each step must be chosen carefully. Over the years, there have been numerous falls on Mexico's pyramids, including this one. These have sometimes resulted in injuries or even death. The ancient steps are smooth and can be slippery. Those who climb in the mountains know that the most dangerous part is always coming down. You are tired, eager to get to the bottom, and gravity works against you. Once you start to fall, your momentum can make recovery impossible.

This completes Part 7 of my Cobá series. I hope you enjoyed it. If so, please leave any thoughts or questions in the Comments section below or email me directly. If you leave a question, please remember to include your email address so that I can respond in a timely fashion.

Hasta luego, Jim