@onlmaps what does "only physical borders" mean? coastlines, mountain ridges, rivers... anything else?
@siljelb A physical border counts as a river, mountain range, a coastline, a clear lowland-highland divide, or a substantial valley, according to author.
Gregory's Server
@siljelb A physical border counts as a river, mountain range, a coastline, a clear lowland-highland divide, or a substantial valley, according to author.