The High Rock sea coast is the region in the upper left corner of the overland map. It is the place where any ships you own are anchored after being bought. Every time you enter your ship via the Transportation Menu, you will be sent to this area. You can actually travel from this location to any other location on the map, both in fast-travel mode and normally. However, it is not possible to travel to this location by any other means than by entering the ship, since your position, which is displayed on the overland map, is too inaccurate to be of real use for the orientation.
To the northwest of this area you can find the entrance to the Mantellan Crux. But since you would normally enter this place via teleportation, this entrance would only be useful under certain conditions (e.g., if you want to re-enter the Crux after leaving prematurely).
- When the player enters any part of the world map where a sizable body of water (e.g. lakes, rivers, etc.) is present, the game will consider them to be in the "High Rock sea coast" region, regardless of whether they are in High Rock, Hammerfell, or anywhere in-between. While there do exist separate regions titled "High Rock bay coast", "Hammerfell sea coast", and "Hammerfell bay coast" in the game's files, none of these are actually used in-game.