Colonial Sites
Points of Interest
Registered Users

About the Project

GeoPACHA (Geospatial Platform for Andean Culture, History and Archaeology) is a browser-based, edited geospatial platform for discovering and mapping archaeological sites in the Andean region of South America. It is designed to facilitate the identification of archaeological sites through “virtual survey” of satellite and aerial imagery and consists of a simple browser-based interface that enables users to visually scan imagery and plot the locations of archaeological sites to a central GIS database using point themes. GeoPACHA also enables the registry of attribute data with site locations via form-based data entry. A grid-based system tracks coverage and sites are recorded.

GeoPACHA is currently in its beta release version. During this initial period, the tool is being used in a targeted manner, focusing on crowdsourcing the locations of previously unmapped colonial settlements (primarily reducciones [planned colonial towns]) that were built during the 1570s throughout much of the Viceroyalty of Peru. Virtual survey is well-suited for these ends because reducciones (and other kinds of colonial-era settlements) are visually distinct from prehispanic archaeological sites, and high resolution satellite imagery for the vast majority of the area of interest is now freely available.

An Edited Crowdsourcing Approach

As is the case for any form of crowdsourced data, quality control is one of our paramount concerns. GeoPACHA’s tiered editorial model is designed to facilitate control of site identifications and attribute data to create high quality, curated datasets. Initial site locations and attributes entered by registered contributors are saved to a queue. Regional editors then conduct initial review of site identifications and attributes. General editors conduct a final review before committing site location and attribute data to the canonical database.

User Access

Access to GeoPACHA is available for three tiers of users: Contributors, Regional Editors, and General Editors. Contributors have the ability to create content by point plotting individual archaeological sites and assigning attributes to them based on information contained in satellite imagery base layers and extracted using GeoPACHA’s measuring tools. Regional editors review and curate this content based on specialized knowledge of specific geographic regions. The general editors manage GeoPACHA’s canonical database and handle user administration.

Access to GeoPACHA at the contributor and regional editor levels is provided following review of credentials and other information from this form. Please contact us if you are interested in becoming either a contributor or regional editor.


GeoPACHA is one of a pair of complementary geospatial tools whose shared purpose is to create rich, expansive datasets for Andeanist historical and archaeological scholarship. The other is LOGAR: Linked Online Gazetteer of the Andean Region. As a digital gazetteer, LOGAR collates information by place – both places that can be assigned fixed geographic coordinates and those (such as imagined geographies and “lost” sites) that cannot.

LOGAR also currently focuses on the reducciones, drawing on several colonial census documents related to Viceroy Francisco de Toledo’s visita general and general resettlement. While GeoPACHA is designed to facilitate discovery and initial documentation of the locations of previously unmapped settlements, LOGAR is designed to compile diverse textual information by place (towns and otherwise). GeoPACHA includes the locations of the reducciones documented in LOGAR (most of which continue to be occupied as modern towns). GeoPACHA and LOGAR together provide the most comprehensive map of colonial towns in the Andes. Over the long run, both will be enriched by contributions from scholars, students, and other interested individuals, who will contribute textual, documentary, and archaeological information.

General Editors

Steven A. Wernke

Vanderbilt University

Parker VanValkenburgh

Brown University

Site Protection Measures

Because of the sensitivities of revealing site locations, GeoPACHA data are accessible only to credentialed, registered contributors and editors. Individuals may request Contributor-level access here.