River

A river is a body of water in the that begins on one side of the town or island and empties into the sea at the other side. Some towns and islands have a river that splits in two, creating an islet. A bridge can be used to cross rivers easily, and in, the vaulting pole can be used to cross rivers before the player receives access to construct bridges. Some species of fish can be caught in the river with a Fishing Rod.

In and, rivers can be shaped differently. They always begin at the east or west of a town, instead of the north. In, rivers can be altered by the player with the Island Designer Construction Permit.

The river mouth is the area where the river meets the sea. Some fish can be caught only in this particular spot. In some towns, there may be two or more of these, increasing the chances of catching these fish.

Islet
An islet, or river island, is a rare geographical feature consisting of a small island in the middle of a river. Islets have bridges connecting them to each riverbank. The islet's length differs in each game. In, they are tiny and are not displayed on the town's map. There is also the possibility of two of them being right next to each other. Bridges connecting them to the mainland can be either north–south or northwest–southeast.

In and, islets are larger than in previous games and each one has a signpost, allowing for a villager or player's house to spawn there. Islets are absent in due to the changes in the river and town's geography, but make a return in, and can be created with the Island Designer Construction Permit unlocked after the player completes Project K by getting at least 3 Stars on the rating of the island. In, islets occur on the map. Due to the size of houses, they have to sit on the islet. This can be good for things like castles with moats.