WMS API

From the dataset abstract

A bilingual map of the City of Helsinki from 1917–18. The map shows the districts, quarters, factory quarters and address numbers, as well as railways, tram lines and ship routes. In addition, the map shows the locations of fire bells, fire stations and mailboxes.

The map scale is 1:8,000 (?) and the image resolution is 300 dpi.

The map can be downloaded as TIFF file and it can also be used via WMS API

The map can be viewed here: https://kartta.hel.fi/link/by2KTt

Coordinate systems:

• Maintained in ETRS-GK25 (EPSG:3879), can be projected to other coordinate systems. See GetCapabilities query for other possible coordinate systems.

API adresses:

• WMS API: https://kartta.hel.fi/ws/geoserver/avoindata/wms

Layers:

• Helsingin_kaupunki_1917_1918

Source: Kartta Helsingin kaupungista vuosilta 1917-18