Open Historical Map

From OpenStreetMap Wiki
Jump to navigation Jump to search
Ohm logo small.png


Open Historical Map (OHM) ( is a site that uses the OSM software stack as a foundation for building an open source, user-editable historical map. This project's goal is to create the world's most universal, detailed, and out-of-date map. OHM will focus on the mapping the geo-objects that OSM is great at mapping - shorelines, political boundaries, buildings, ways, and points of interest. Future and other efforts may engage in discussing historical actions, events, people, and movable items.

For First Time Visitors

(and anyone looking to refresh their memories)

Newcomers should visit the Open Historical Map/OHM Basics page first.

OHM resources

The new Open Historical Map/Resources page provides a place to list map, imagery and documentary sources that are appropriately licensed for use in the OHM project.

Editing Maps in OHM

This page of the OHM wiki is currently being revised. Much has been moved to Open Historical Map/OHM Basics. Look there for an introduction to OHM editing.

Information about using historic imagery and maps with OHM is being put in the new Open Historical Map/Imagery page.

How to map

A new Tagging page is under development.

Further notes

For further in depth tagging of features, you may consider Comparison of life cycle concepts, in particular the date namespace suffix and the lifecycle prefix.

Using the data

There are a variety of ways to use OpenHistoricalMap Data.

For smallish scale it is possible to download data using JOSM. Two alternatives now exist for larger volumes of data or larger areas:

See also these pages for the legal attributions:

Short-term plans

Plans have been moved to the new planning document Open Historical Map/Plans.

Keys proposed

Related OSM Projects


The list of places to talk OHM has been moved to Open Historical Map/OHM Basics#Communities

OHM-related mashups