City Resource hosts maps of all kinds, mostly those which intend to make an argument. For instance, the 1966 Map of Mumbai (Bombay), when overlaid on the current OSM, one can see how the mud flats are built upon, with no flood mitigation plan in place. Below are some useful web maps showing Bombay's evolution. The 'Other Cities' section hosts old maps of Vasai Virar, Mira-Bhayandar, Bengaluru, Chennai, Delhi, Panvel, Chatrapati Sambhaji Nagar (Aurangabad), Nasik, Raigad District (part) and Chilka Lake in Orissa.
(click on a map to view it overlaid on satellite imagery in a new window)
To see all historical maps as webmaps on a single page, click here
You can draw lines points and polygons on the map and write notes. This data can be downloaded in geoJson format, which opens in QGIS. This can be converted to kml using online conversion tools to see it inside Google Earth Pro. This is useful while mapping collaboratively.
This work is licensed under a Creative Commons Attribution 4.0 International License