Revel Immortal 0.8 Alpha update is out, and notably adds local region maps and fast travel.
Maps are represented as a 1 pixel per tile, or 1:16 ratio.
Garranshall is composed of 80x80 maps, of 40x40 tiles each; this means the map of garranshall is 3200x3200 pixels.
Around the map you can find markers which allow you to fast-travel to these locations.
Most of the markers so far are present and travelable in Garranshall from the start of the game; this is only because it is assumed that Morning would know locations of castle Iridine and Garranshall quite well.
By default unless explicitly learned about, or discovered first-hand map markers are not present. When locations are learned of second-hand, the markers are shown but are not fast-travellable until arrived at manually.