Douwe Dabbe is mapping old pictoral city maps from a couple of hundred years ago to their current geographical location.

The resulting maps are on offer for free (gratis) as OpenStreetMap overlay's in combination with the excellent android mapping app OsmAnd.

These Historic city maps are 'Great Works of Art' and best viewed on a tablet or a large screen phone.

Accuracy varies (10m. - 50m.) naturally as these maps are old and made with simple tools and places did change a lot over time.

Osmand provides a transparancy slider, one sees through to the current situation.

Osmand can be had (free and paid versions) from any appstore or their site www.osmand.net

and the historic city maps and the installation instructions can be found on: www.geotiek.nl