Town & castle walls (synonyms: perimeter walls, fortifications, palisades) are fortifications that encircle a town, castle, fort, or other similar location. They may be combined with a moat. They may be constructed from stone, wooden palisade, or other materials (post-apocalyptic worlds may use shipping containers, while dark fantasy worlds may feature bone walls). These walls may contain gates, gatehouses, watchtowers, or bastions. During sieges there may be sapping tunnels underneath, and siege towers and ladders against them. These walls may have secret ways of getting through or around them such as sewers, grates, or underground rivers that connect to wells within the interior of the wall. Town and castle walls are home to guards and intruders.

Sneaking through, under, or over a town wall is a common occurrence in narrative worlds.

When designing town and castle walls for fictional worlds, consider the height these walls reach. In fantasy worlds they may be a portion of great wall. Also consider if the structure itself is simply a wall, or if there are houses, barracks, watchtowers, or other structures built into the wall or perched atop it.

Town and castle walls may incorporate local terrain features. For example, walls may connect karsts or mountains. They may surround lakes or help protect sea ports or docks within a town or castle. Walls may even be carved from the local terrain.

Moats

Palisades

Gatehouses

Town and city walls may have been built section by section over long periods of time. The oldest sections of the wall are likely to be towards the middle of the settlement.

Town walls are a defensive measure, and there may be catapults, canons, gun emplacements, or other weapons placed along or atop them.