Piedras Negras is the modern name for a ruined city of the pre-Columbian Maya civilization located on the north bank of the Usumacinta River in the Petén department of Guatemala. The name Piedras Negras means "black stones" in Spanish. Its name in the language of the Classic Maya has been read in Maya inscriptions as Yo'k'ib', meaning "great gateway" or "entrance", considered a possible reference to a large and now dry sinkhole nearby. 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 seems to have been an independent city-state for most of the Classic Period, although sometimes in alliance with other states of the region and perhaps paying tribute to others at times. It had an alliance with Yaxchilan, in what is now Chiapas, 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.
The panel 12 of Piedras Negras showed three neighboring rulers as captives of the ruler C of Piedras Negras. One of the captives might be the ninth king of Yaxchilan, Knot-Eye Jaguar I, who kept reigning after the panel was made. As late maya subservient rulers were often depicted as bound captives in spite of keeping ruling their own kingdoms, the panel suggests that Piedras Negras might have established its authority in the nearby area, i.e. the Usumacinta drainage, in about 184.108.40.206.0 Period Ending, which corresponds to 514 AD.
Piedras Negras had been populated since the 7th century BC. The population of Piedras Negras seems to have reached the peak for twice. The first population peak happened in the preclassic era, around 200 BC, and was followed by a decline.  The second population peak of Piedras Negras happened in the late classic era. It happened in around the second half of the 8th century AD, during which the maximum of Piedras Negras' population is estimated to be around 2 600. At the same time, Piedras Negras was also the largest polity in this region. The total population of the polity at this time is estimated to be around 50 000.
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 in 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.
A unique feature of the monuments at Piedras Negras is the frequent occurrence of the so-called "artists' signatures". Individual artists have been identified by the use of recurring glyphs on stelae and other reliefs.
Ruler 7 (reigned 781-808?) of Piedras Negras was captured by K'inich Tatbu Skull IV of Yaxchilan. This event was recorded on the lintel 10 of Yaxchilan. Piedras Negras might be abandoned within several years after this event.
Before the site was abandoned, some monuments were deliberately damaged, including images and glyphs of rulers defaced, but images and glyphs of deities left intact, suggesting a revolt or conquest by people literate in Maya writing.
An archeological project at Piedras Negras was conducted by the University of Pennsylvania from 1931 to 1939 under the direction of J. Alden Mason and Linton Satterthwaite. Further archaeological work here was conducted from 1997 to 2000, directed by Stephen Houston of Brigham Young University and Hector Escobedo of the Universidad del Valle de Guatemala, with permission from the Instituto de Antropología e Historia de Guatemala (IDAEH).
Mayanist Tatiana Proskouriakoff was the first to decipher the names and dates of a Maya dynasty from her work with the monuments at this site, a breakthrough in the decipherment of the Maya Script. Prouskourikoff was buried here in Group F after her death in 1985.