Wall

Cobblestone walls are decorative blocks. There are 3 types: cobblestone walls and mossy cobblestone walls.

Obtaining
Cobblestone walls can be mined using any pickaxe. If mined without a pickaxe, it will drop nothing.

Usage
Cobblestone walls are one and a half blocks tall for player/mob collision, and one block tall for all other purposes, similar to fences. This prevents players and mobs from jumping over them, while using only one actual block space. A wall occupies the center space of blocks and automatically connects to any solid block that is placed next to it. Since their hitbox is smaller than a single block, it will allow a mob in the block to breathe even when submerged.

Cobblestone walls are more efficient at fencing off mobs than a two-block high wall of cobblestone, costing only half as many blocks, and being more space-efficient as well. The drawback, however, is that a skeleton might shoot over the wall, a creeper could explode if a player is standing near the wall and a spider could still climb over the wall.

Unlike fences, if two cobblestone walls are placed one block apart diagonally, you cannot walk between them.

Trivia

 * When a fence gate is placed between 2 cobblestone walls (of either type) it will stoop down slightly to match the height of the cobblestone wall.
 * If the fence gate is placed next to only 1 (mossy) cobblestone wall, or vice versa, it will not lower.
 * Although the cobblestone wall only raises at corners and ends, it will raise to support a solid or non-solid block placed above it.

Gallery
Bruchsteinmauer Muro de roca Muret 丸石の壁 Keistenen muur Murek z bruku pt-br:Parede de Pedregulho Булыжниковая стена 圆石墙