Plus towns and secondary roads.
I’ve recently been playing with procedural map generation, which has been kind of an obsession of mine for awhile. Some output is seen below, in both fantasy map style and satellite map style.
Source code is available at https://github.com/rileypb/worldgeneration.
A lot of inspiration came from https://mewo2.com/notes/terrain/ and from http://www-cs-students.stanford.edu/~amitp/game-programming/polygon-map-generation/, who has more recently made this brilliant toy: https://www.redblobgames.com/maps/mapgen4/.