Several hundred settlements from the time between 500 and 1400 AD lie in the Bolivian Llanos de Mojos savannah and have fascinated archaeologists for years. Researchers from the German Archaeological Institute, the University of Bonn and the University of Exeter have now visualized the dimensions of the largest known settlement of the so-called Casarabe culture. Mapping with the laser technology LIDAR indicates that it is an early urbanism with a low population density - the only known case so far from the Amazon lowlands. The results shed new light on how globally widespread and diverse early urban life was and how earlier societies lived in the Amazon. The study appeared in the journal Nature.
More than 20 years ago, Dr. Heiko Prümers from the German Archaeological Institute and Prof. Dr. Carla Jaimes Betancourt from the University of Bonn, at that time a student in La Paz, began archaeological excavations on two “mounds” near the village of Casarabe in Bolivia. The Mojos Plains is a southwestern fringe of the Amazon region. Even though the savannah plain, which flooded several months a year during rainy season, does not encourage permanent settlement, there are still many visible traces of the time before Spanish colonization at the beginning of the 16th century. Next to the “mounds”, these traces include mainly causeways and canals that often lead for kilometers in a dead straight line across the savannahs1.
Initial conventional surveys revealed a terraced core area, a ditch-wall enclosing the site, and canals. In addition, it became apparent that some of these pre-Hispanic settlements were enormous in size. "However, the dense vegetation under which these settlements were located prevented us from seeing the structural details of the monumental mounds and their surroundings," says Carla Jaimes Betancourt from the Department for the Anthropology of the Americas at the University of Bonn.
- 1. "This indicated a relatively dense settlement in pre-Hispanic times. Our goal was to conduct basic research and trace the settlements and life there," says Heiko Prümers. In earlier studies, the researchers already found that the Casarabe culture - named after the nearby village - dates to the period between 500 and 1400 AD and, according to current knowledge, extended over a region of around 16,000 square kilometers. The “mounds” turned out to be eroded pyramid stumps and platform buildings.
Heiko Prümers, Carla Jaimes Betancourt, José Iriarte, Mark Robinson & Martin Schaich. Lidar reveals pre-Hispanic low-density urbanism in the Bolivian Amazon. Nature, 2022 DOI: 10.1038/s41586-022-04780-4
Archaeological remains of agrarian-based, low-density urbananism have been reported to exist beneath the tropical forests of Southeast Asia, Sri Lanka and Central America. However, beyond some large interconnected settlements in southern Amazonia, there has been no such evidence for pre-Hispanic Amazonia. Here we present lidar data of sites belonging to the Casarabe culture (around AD 500 to AD 1400) in the Llanos de Mojos savannah–forest mosaic, southwest Amazonia, revealing the presence of two remarkably large sites (147 ha and 315 ha) in a dense four-tiered settlement system. The Casarabe culture area, as far as known today, spans approximately 4,500 km2, with one of the large settlement sites controlling an area of approximately 500 km2. The civic-ceremonial architecture of these large settlement sites includes stepped platforms, on top of which lie U-shaped structures, rectangular platform mounds and conical pyramids (which are up to 22 m tall). The large settlement sites are surrounded by ranked concentric polygonal banks and represent central nodes that are connected to lower-ranked sites by straight, raised causeways that stretch over several kilometres. Massive water-management infrastructure, composed of canals and reservoirs, complete the settlement system in an anthropogenically modified landscape. Our results indicate that the Casarabe-culture settlement pattern represents a type of tropical low-density urbanism that has not previously been described in Amazonia.
