The Volatile Wastelands are an area of extreme volatility in reality - namely, where it pretty much decided to divide by zero. They only marginally obey the known laws of time or physics, and are overall exceedingly dangerous.
The region is near the Center of the Multiverse, which is where the entire Multiverse started, and is likely a relic from this time - a very dangerous relic. In fact, it probably was the entire Multiverse for a time before things started actually coming in.
Things Unify into the Volatile Wastelands all the time, but only rarely are they living things. Often these things Unify above your head and as such you need to avoid them - not an easy task, considering they may vaporize in mid air, be replaced, may move spontaneously, or the ground might do any of these things as well. Weather is also unstable. Just about the only thing that you can be guaranteed of is the breathability of the atmosphere - and even that can be dangerous. People have gone into the Volatile Wastelands and never returned.
This area is also where Nightmares come from - in fact it's where they originated back in the initial Nightmare War. At present, in the area some Nightmares have semi-permanently encamped in Metrotitan, a cityformer similar to Metroplex except in Nightmare form. They have not had any detectable activity for several months as of February 12, 2008 (RL time).
There are several large, barren areas surrounding the Volatile Wastelands. There are also other areas of abnormal physics nearby, though few are anywhere near as dangerous. Though geographically isolated, eddies and currents of the Volatile Wastelands are in different places in the Multiverse, and although they are nowhere near as dangerous, they make travel through certain regions difficult, not unlike an ocean. Even flying over them is a bad idea.
In general, the Volatile Wastelands are a TP centric area. RPing in them is not usually done, and by doing so you might get yelled at by an admin - it is an exceedingly dangerous place.