Geography

Ancient World Mapping Center

Interactive Map of the Roman World (works best in Chrome & Safari). Old version of the site here.

CIA World Factbook

Historical Atlas of the 20th Century

Internet Resources for Geographers

Perry Castaneda Library (PCL) Map Collection at University of Texas

PCL Outline Maps

Water Risk Atlas

22 Maps that Show Regional (US) Speech Differences

Linguistic Maps - MuturZikin