Google Maps

Modern Maps

Harvard Geospacial Library The site allows to download geographic data for use with GIS software.

Japan GIS Resources  via China Historical GIS

JapanMap Created by Lex Berman originally for 2011 Japan disaster, JapanMap allows to view Japan with many layered information such as nuclear power plants, railway network, local fire stations.

国土地理院 The Geospatial Information Authority of Japan (GSI)

Topographic Map of Japan, 1/25,000 scale ウォッちず 国土地理院地図閲覧サービス
Offered by the Geographical Survey Institute; Map of Japan in 1/25,000 scale is viewable.

国土変遷アーカイブ 空中写真閲覧

GIS related information

Historical Maps 歴史地図

National Archives' Digital collection: Modern maps 明治以降

Japanese Historical Maps, UC Berkely

Japanese Maps of Tokugawa Era University of British Columbia's 275 maps are veiwable.

Historical Maps of Asia, Perry-Castañeda Library Map Collection, University of Texas at Austin

国会図書館絵図検索 535 historical maps are searchable, some with images. 

Complete Survey of the Japanese Coast 大日本沿海輿地全図
The first geographical survey maps of Japan, made by Tadataka Ino, and often known as the Ino maps 伊能図. This site provides digital images of 43 sheets, as well as options to view the entire map (some sheets have been lost) and to zoom in. There is also a comprehensive geographical name index including old, modern, and natural place names. Created by the National Diet Library.