The University of Manchester Library

Approx. 150,000 sheets, 800 atlases.
Topographic coverage of UK at 1:25,000 and smaller scale; 1:10,000/10,560 regional coverage; 1:2500/1:1250 local sheets.
A number of thematic map series for the UK are held, including Geological Survey and Soil Survey; also hydrogeology and geophysical, land use and land classification maps.
Historical mapping of the North West, generally, and Greater Manchester in particular, is excellent, including some pre-OS facsimiles and 1:500/1:1056 town plans of Manchester & Salford.
Special Collections housed in the Main Library building are from the Manchester Geographical Society, books and atlases AND
the Mills collection of mostly 16th-19th century maps.
There is medium scale coverage for most countries of the world.
Admiralty Charts for UK and some world coverage are available to consult.

There is a good collection of cartographic texts, map monographs gazetteers/ street indexes and atlases held in the Purple Ground area.
A wide range of electronic resources can be accessed, including the Digimap Collections - UK topographical, geology and historical.
More information can be found at http://www.library.manchester.ac.uk/search-resources/guide-to-special-collections/map-collection/