The Archaeology of Greater London online map is a GIS-based online mapping application curated by the Museum of London (MOLA). Created under a partnership with Historic England, the map (2015) is the digital companion to the print publication The Archaeology of Greater London (2000) which may now be freely downloaded from MOLA's website.
A detailed How to guide helps users orient themselves to the application and use the map.
Taken from the project website (accessed 2016-06-01):
These maps present a selection of the most notable finds and sites from London's prehistoric, Roman, Saxon, and medieval past, all shown over the modern landscape. You can explore them by clicking, holding and dragging the cursor on the map, and you may zoom in and out using the mouse wheel or the plus and minus buttons. You can even see the notable finds made in your local area by clicking on the magnifying glass icon and typing in a road name. A summary of each map is provided on the left of the screen, while the legend on the right provides a key to the finds and sites represented by the points. Each map also shows the main water courses and the generalised surface geology of the Greater London area, both of which have played their part in determining how the region was occupied. When viewing all of London, the general concentration of finds is shown as a coloured layer, while zooming in will display the find spots themselves. Clicking on an individual point displays more detail for it, including its period, and the borough in which it was found.