Piedras Negras is the modern name for an ancient, ruined city of the pre-Columbian Maya civilization located on the north bank of the Usumacinta River in the Petén department of northwestern Guatemala. The Mayan name for the city was Yo'k'ib' ([ˈjoʔkʼib]) or Yokib'. Piedras Negras was one of the most powerful of the Usumacinta ancient Maya urban centers. Occupation at Piedras Negras is known from the Late Preclassic period onward, based on dates retrieved from epigraphic information found on multiple stelae and altars at the site. Piedras Negras is a priceless archaeological site, known for its large sculptural output when compared to other ancient Maya sites. The wealth of sculpture, in conjunction with the precise chronological information associated with the lives of the settlement's elite, has allowed archaeologists to reconstruct the political history of the city's polity and its geopolitical footprint.

Piedras Negras is located in the Southern Lowlands of Guatemala, very close to the border with Mexico.

Piedras Negras is located along the eastern banks of the Usumacinta River. The settlement is oriented around plazas, without a grid system. The polity is built into a series of hills, offering a natural defensive structure, and is currently heavily forested.

The name Piedras Negras means "black stones" in Spanish; in the language of the Classic Maya, the name has been read (in Maya inscriptions) as Yo'k'ib' ([ˈjoʔkʼib]), meaning "great gateway", or "entrance", considered a possible reference to a large (and now dry) sinkhole nearby. It may also have been a reference to its location as a prominent intermediary along the trade routes leading to the Tabasco floodplain. Some authors think that the name is "Paw Stone", but is more likely to be the name of the founder, as hieroglyphs on Throne 1 and Altar 4 show.

Piedras Negras had been populated since the 7th century BC. Its population seems to have peaked twice; the first peak occurred in the Late Preclassic period, around 200 BC, and was followed by a subsequent decline. The second peak happened in the Late Classic period, around the second half of the 8th century, during which the maximum population of the principal settlement is estimated to have been around 2,600 people. At the same time, Piedras Negras was also the largest polity in the region, with a total population estimate of around 50,000.

Piedras Negras was an independent city-state for most of the Early and Late Classic periods, although it may have been allied with other adjacent states and may have paid-tribute to others, at times. It had an alliance with Yaxchilan, in what is now Chiapas state, Mexico, some 40 km up the Usumacinta River. Ceramics show the site was occupied from the mid-7th century BC to 850 AD. Its most impressive period of sculpture and architecture dated from about 608 through 810, although there is some evidence that Piedras Negras was already a city of some importance since 400 AD.^{[citation needed]}

Panel 12 of Piedras Negras shows three neighboring rulers as captives of Ruler C. One of the captives might be the ninth king of Yaxchilan, Joy B'alam (also known as Knot-Eye Jaguar I), who continued to reign after the panel was made. As subservient rulers were often depicted as bound captives, even while continuing to rule their own kingdoms, the panel suggests that Piedras Negras may have established its authority over the middle Usumacinta drainage in about 9.4.0.0.0 (514 AD).

The artistry of the sculpture of the Late Classic period of Piedras Negras is considered particularly fine. The site has two ball courts and several plazas; there are vaulted palaces and temple pyramids, including one that is connected to one of the many caves on the site. Along the banks of the river is a large boulder with the emblem glyph of Yo’ki’b carved on it, facing skyward.^{[citation needed]}