[G] FFE on Arid Plateau and Entombed Valley

The basic wall-off looks like this:



The cannon covers all buildings, and the only way for lings to run into the main is to go around the nexus, and through the small area between the vespene geyser and the mineral patch. This area is easily blocked with probes, or a pylon, as seen here:



An additional building can be placed to reinforce your pylon and cannon from banelings:



What i find most promising about an FFE on this map shown below:



These three pylons form a complete wall off. Its certainly not an impenetrable wall off, but it can serve to buy time and protect cannons placed behind the pylons. This feature will help immensely for dealing with roach-ling allins.

Finally, one more building is enough to completely wall off the mineral line if this is deemed necessary:



Here's an alternative way to wall-off taken from the thread.

There are a few ways to go about walling off, but this is the way i found to be most effective.



The purpose of the second pylon is to both wall off, and give the power radius required for your second cannon. This cannon covers the rocks from zergling attacks, and also covers most of the ramp for additional defense. Note that like on Nazarim Crypt this cannon does not need to be built right away, or even at all if zerg chooses not to try to kill the rocks with lings. However, unlike on Nazarim Crypt it is hard to use a zealot to defend this kind of harass.

In case of an all in a gateway and a cannon can wall off your side entrance, and cannons can be positioned to defend both entrances: