Geographers' Map Company Ltd. (A-Z Maps) was established in London on 25 August 1936. The company's most famous publication, the iconic A-Z Atlas and Guide to London, was created by Phyllis Pearsall, the founder of A-Z, who explored every street in London to create the first edition. Since then, A-Z has become the trusted source for street maps and atlases, as well as developing Visitors' Guides, Road Atlases and the Adventure Map series for walkers.