Activating the violet gate isn't too hard, and doing so seems to cause all your senses to shift. The worlds blur together, and you're left in a greyish wasteland.
You find yourself under an archway looking out upon a rolling set of hills of rock and dirt in all directions. To the west, you see a large number of creatures milling about, burdened with chains and working towards some task. You recognize three of the creatures, though they are fairly distant... a drow, a human mage, and a monster that you awoke in the first room of this adventure. The monster is being visibly beaten into submission by a larger beast of burden that looks like an undead half-giant.
In all there are hundreds of such creatures, and it seems as though they are constructing something of a pyramid in this waste. It is only half-way constructed from the appearance of things. A strange cluster of loose tattered cloth robes drape over a vaguely humanoid shape a hundred feet above it.
This whole area is lit, the sky is a cloudy purple and grey, but luminescent. The place is cold, but not to the point of discomfort. A strange dead place.
More buildings, much smaller, appear to the north, south, and east. They all look more like ruins of something past. You can make out the shapes of horses or something of that general proportion near the ruins to the south. The tower fallen to the east looks like it was once massive, but has crumpled in on itself. To the north, a temple of some sort seems to have been even more crushed and crumbled, only some few salty looking pillars remain.