Cobblestone wall is a block designed for decorative purposes such as gardens and are an alternative to fences. There are 2 types: cobblestone walls and mossy cobblestone walls. They work very similarly to fences, as they are 1.5 blocks tall to mobs. Cobblestone walls are more efficient at fencing off mobs than a two-block high cobblestone wall, 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 or a creeper could explode if a player is standing near the wall.