The map shows Japan in 1570 CE, near the end of the "Sengoku Jidai", the 'Warring States period'. This coincides with the end of the Muromachi and Ashikaga periods. Only Japan is shown, the countries on mainland Asia are not detailed. The map area is divided into the traditional provinces, which only partially match the modern prefectures. The province borders and roads are not exact, which becomes apparent when zooming in, but give a good overview of the general layout. Major towns, cities, temples, roads and geographical features are also shown; rivers are not marked, though being important transportation routes. The sizes of the settlements are mostly conjecture, as there is little data available for them before the Edo period. This is very much a castle map; several hundred of them are shown, though most small forts and fortified houses have been omitted. Some of the routes shown on the map are well known; others are partly guesswork. Several roads have been formalized during the Edo period, but as these "kaido" were based on ancient routes, have been included nonetheless.
The map has been made with the help of OpenLayers.
You can zoom out and in, pan the view and enlarge the map to occupy the full screen.
Four different layers are available.
None of them is transparent, so it does not make sense to switch on multiple ones at the same time.
Zoom out for less detail, or back in for more.
Hover over a landmark to see a short description (displayed below the map like the coordinates of the mouse position).
Note that modern Japan is in several areas heavily urbanized.
Cities which show up as large blots on the background layers would appear as mostly farmland or wilderness in the 16th century CE.
Bridges that connect islands, harbor piers that extend into the sea and other large scale modern structures did not exist at the time.
Also the coastline, sizes of lakes and courses of rivers were somewhat different at certain locations.
In general, there was more water, in the form of marshes and settlement lying closer to rivers and coasts.
This is the high (or low) point of the Sengoku Jidai.
The Ashikaga shogunate is teetering on the brink of destruction.
Various powerful sengoku daimyo are waging war among each other, several ones maneuvering to conquer the capital Kyōto and establish themselves as the new shogun.
The strongest clans are the Amago, Ashina, Asakura, Azai, Chosokabe, Date, Hōjō, Miyoshi, Mogami, Mōri, Nanbu, Oda, Otomo, Ryuzoji, Satake, Takeda, Tokugawa and Uesugi.
The Ikkō-ikki movement is also causing uprisings.
The three great unifiers, Oda Nobunaga, Toyotomi Hideyoshi and Tokugawa Ieyasu, have not gained dominance yet.
For some three centuries, both trade and population have grown, despite all the fighting.
For Japan, trade is at its peak, to be almost stamped out in the next century by the Tokugawa shogunate.
In 1570 CE, Chinese goods and European guns and missionaries are still coming to the country in large numbers.
Nagasaki and Hiroshima are absent, not because the Americans have bombed them, but because they have not yet been founded.
Edo restrictions on freedom of movement and carrying weapons are not yet in place.
Many countryside settlements are condensing into villages.
Also many daimyo have built and are building castles.
Most of these are small fortresses guarding roads and mountain passes.
There are "yamajiro" (mountain castles), "hirayamajiro" (hilltop castles), "hirajiro" (flatland castles) and "numajiro" (wetland castles).
Some of them are larger and form the nuclei of "jokamachi", villages or even towns, classifying themselves as true castles.
However most still have a strictly military function; the lords make their living in "yakata", fortified manor houses, in the valleys below.
In the later Edo period many of the mountain castles will be abanonded and several lowland yakata expanded into sprawling castles.
Data on 16th century Japan, unlike 17th and later centuries, is scarce. The websites below offer good information:
- http://jcastle.info/: Very large list of castles and forts
- http://www.japancastle.jp/: List of castles with good descriptions
- https://www.japanvisitor.com/japan-city-guides/japanese-castles/castles-a-z: Fair list of castles
- https://sengokujidai.org/sites%e3%80%8c%e5%9f%8e%e3%83%bb%e5%af%ba%e3%80%8d/castles/: Fair list of castles, partly in Japanese
- http://www.japanese-castle-explorer.com/: Small list of castles that are still standing or have been reconstructed, also with interactive map
A good introduction to Japanese castles in general is "Japanese Castles 1540 - 1640", by Stephen Turnbull, Osprey Publishing, ISBN 1-84176-429-9.