Nether Brick Fence

Nether Brick Fences are part of Nether fortresses. They make up the barred windows in the tunnels and also the railings in the balcony room.

Natural Occurrence
Nether brick fences are naturally found in Nether fortresses where they form window bars and gate-like structures.

Usage
Nether brick fences do not burn and have the same blast resistance as most stone blocks, which makes them useful in creating Ghast-proof structures. In areas frequently bombarded by Ghasts, Nether brick fences are useful for shielding light sources. They connect to most blocks, including wooden fence gates, in the same manner as wooden fences. However, they do not connect to wooden fences. By combining sections of the two types of fences, it is possible to make barriers that players can navigate through, but most mobs will get stuck in. However, one should bear in mind, that in case there is a group of monsters trying to get to the player (e.g. a mob of zombies), the ones in the back can easily push the ones in the front through this kind of a fence, because collision allows it.

Trivia

 * Nether brick fences require 6 Nether brick for 6 pieces, but 6 sticks would only craft into 2 fences.
 * They also require blocks, while normal wood fences require sticks (also blocks in 1.8, but not completely).
 * Leads can be attached to Nether brick fence.
 * They are the only fence variant that has no gate.