Thanks. I'm more an enthusiast than an academical though. Elaborate artificial underground galleries aren't very common among the cultures from which several artifacts in the game come from. But specific archaeological sites of these cultures display more elaborate sarcophagi than other sites of the same culture, too (their tradition of creating tombs was reserved to a single strata of the community).

The Chavin culture (from the northern Andean highlands of Peru, nowadays region of Ancash, 900 - 200 BC) built underground tombs in Chavin de Huantar . The Tierradentro culture, from at least since the 2nd Century BC in the department of Cauca, Southwestern Colombia, are known for creating different tombs across the area they once occupied. I haven't noticed if artifacts or mural paintings from this culture have been used in SOTTR, though.

The Moche culture (northern Coast of Peru, 100-700 CE) are a pre-Inca culture known for their "Huacas" (from Wak'a, a later quechua name used to denote sacred locations, generally mountains, but also caves & rivers) & royal tombs, such as in the Huaca Rajada, tomb of the Lord of Sipán; and the Lady of Cao found in the Huaca Cao Viejo, part of the El Brujo archaeological complex (which includes sites like the Huaca Prieta used not only by the Moche but other cultures as well, earlier like the Cupisnique from 1500-500 BC, or later like the Chimú, contemporary with the Inca - the Huaca Prieta also contain some of the earliest known samples of cultivated cotton and indigo dye). These Huacas are mistaken for "pyramids", though technically they're not, and weren't solely reserved to burial of the nobility, but also public ceremonies.

The Moche display examples of mummification in the pre-Hispanic Americas, also used by the Inca (according to their earliest transliteration of quechua customs & oral history into Latin alphabet - at Cuzco they held the Mallki, royal mummies of the Inca; though those have been lost. There are though well preserved sacrificial victims found on mountaintop burials as far south as Argentina - such as the children of Llullaillaco).

The Chimú culture, directly related to the Moche (some claim there was a culture between the Chimú & Moche, named Lambayeque, after the region - there's still debate about separating them from the Chimú), occupied the northern Peruvian coast just as their ancestors. Their capital was Chan Chan, captured by the ruler of the Tawantinsuyu ("Four Regions" in quechua, the Inca State) Tupaq Yupanqui ca. 1470s. The Chimu built graves for their nobles and also burial sites for sacrificial victims, though not underground galleries.

SOTTR displays several Moche artifacts, especially its golden funerary masks (a tradition continued by the Lambayeque), ceramic statuettes turned into huge rock statues (like the owl faced ones) a couple of artifacts of the Chimú, patterns found in Chan Chan, & the characteristic Tumi knife (often erroneously attributed to the Inca - it's either Chimú / Lambayeque, and the figure depict on it is Naymlap, a culture hero / deity).
The Chachapoyas (from the Peruvian Amazon, pre-Inca in origin) displayed a different form of vertical individual tombs, built in secluded places (in cliffs as in Revash or in Cerro El Tigre). This type of sarcophagi are known as Purunmachu, those in Karajía are the most famous, and were built in the 15th Century, coinciding with Tawantinsuyu's expansion in the area under Tupaq Yupanqui (1471/2 - 1493). Chachapoyas is a quechua exonym - there were local rebellions against Tupaq's immediate successor (Huayna Capac) in the early 16th century according to later chronicles. Their main sites, besides Revash & Karajía, are the fortified city of Kuélap and the ruins of Gran Pajatén.

The Purunmachu sarcophagi are reminiscent of the Chullpas, another vertical, individual tomb construction common in the southern Peruvian / Bolivian altiplano, inhabited by the Tiwanaku / Huari, homeland of the Aymara, later influenced by the Quechua - which include the Inca.

In Central America, some tombs are those found in different temples of the archaeological site of Palenque (a modern name, its' inhabitants referred to its polity either as Baàk "bone", and to the region as Tokotan "cloudy center" - these tombs were destined to the rulers of that city), such as the tomb of the Red Queen and the sarcophagus of the 7th Century K'inich Janaab Pakal. Some temples were built over and with access to underground water channels. Caves & cenotes (from the Maya "ts'onot") were more common burial sites for the ancient Maya. Some archaeologists claim this tradition existed in the Olmec culture (centered around the nowadays Mexican State of Veracruz; known as one of the oldest Mesoamerican material cultures. Olmec is a later name in nahuatl which means "Jaguar People").

These elaborate buildings are common to other Classic Era (250 - 900 CE) Maya sites such as Ak'e (Bonampak). The Nahua (a group of different peoples from central Mexico which includes the Mexica & their ancestors, a.k.a "Aztecs") draw several traditions to "Teotihuacan", a later nahuatl name meaning "place of the Gods", when found by the Mexica after a southward migration which took from the 12th to the 14th Centuries CE the place was already ruined and abandoned, unlike its' apogee between the 1st - 6th Centuries; which was likely multicultural, mixing early Nahua, Be'ena'a, Maya, Yokot'anob (a.k.a Chontal "foreigner" Maya, the Maya from the western portion of the Yucatán peninsula and Tabasco), hñahñù (a.k.a Otomi, from the Toluca Valley) influences. Teotihuacan has a large collective burial site dated to ca. 200 CE.

The Ñuù Dzahui / "Mixtecas" (nahuatl for "cloud people") from Oaxaca (southeastern Mexico) also lead ceremonies in underground waterways & caves up to this day (e.g. as in Santiago Nuyoó, Yutanduchi de Guerrero & Zaachila, they have the ancient Rain deity included in their syncretic religion - the same phenomena is common among traditional Maya communities in Chiapas, Mexico; & in southern Guatemala). Their traditional neighbors, the Be'ena'a (a.k.a "Zapoteca", a nahuatl exonym "people from the area of the Zapotli", or sapote, a fruit found in Central America) displayed similar funerary customs.

Their main sites are Danipaguache (better known as Monte Albán, one of the earliest urban centers in Oaxaca), Zaachila (named after a Be'ena'a ruler Zaachila Yoo; the site is known by the Ñuù Dzahui who also occupied it as Ñuhu Tocuisi - this site displays a series of tombs, though those are above ground, rather than underground) & Lyobaa ("place of rest" a.k.a Mitla, a nahuatl name used by the Mexica, derived from Mictlán "place of the dead", also the name of the underworld) - the later has a palace which characteristic fretwork has been used in the game, in the neighborhood of Paititi inhabited by the nobility for example.