The Open Grave

Surrounding the open wound, in about a 15 mile radius there is little to no larger wildlife, and in about a 5 mile radius, there is no life at all. In the last day, there is a scouting party (warriors on Xill Spider Mounts.), and closer still are scouts that will bolt to the wound when they see the party (perception dc 28 to see him first, dc 20 to see him run away once it's too late, or about 200 ft.
The Xill spiders are huge hulking things, with long dark blueish hairs, and unusually large clusters of eyes above their massive fangs. They are capable of moving in quick bursts, and the xill will usually strap themselves to the spiders to avoid falling off once the spiders attack. This still happens very regularly, and the xill need a dc 5 flat check or fall off if the spider attacks, and dc 11 if it attempts a grapple or web. The ravine, created recently in an earthquake shortly after the return of magic, reaches down 120 feet, and runs for miles to the east and west. At its deepest point, you can see an intricate city beneath, mostly destroyed by rubble and covered in thick spider webs. The city beneath has been dug through, and all valuables scoured from it.
From the remains of the city, they can deduce a number of things about the Xill civilization. The entire city seems to have been walled not only around, but also over, and large pillars reach from the ground at regular intervals. And parts of the city that still remain mostly intact show them reach more than 100 ft into the air, with large arches reaching between them (and covered in large clusters of spider web).

Notable Places

The Ritual Hall: A huge coliseum shaped arena, which was traditionally used for religious worship. At the very center, a raised stage with an altar covered in runes, and ash covers the stage in what resembles a blast pattern. On the stands painted in ash are silhouettes of thousands of Xill (think Pompeii shadows). This is where the ritual that took their souls took place.
The Spider Hatchery: A large stretch of land where Xill spiders are bred, raised and trained. It contains large glass hexagonal structures intended to keep the spiders in. Most of these structures are broken now. Clusters of eggs are stacked in long 20 ft tall panels, with temperature and humidity controlling structures in between, and platforms you could climb between for workers to clean the eggs and remove the spiders once hatched.
Aravis' Chambers: A prison and torturer/executioners chambers. The rooms range from what looks like small inn rooms, to sarcophagi built into the walls. Named for Aravis, God of the Damned. Those committed to these halls had 13 days to prove their soul could be saved, and if they could not, were doomed to the chambers for the rest of their (short) lives. Usually when released, they would be shunted to the lowest level of hierarchy, and life on the surface. The Executioner still lurks the halls, bound by his purpose by the Xill Ritual. He is basically a bone devil now (elite template). In his chambers they find a log of all the people he executed, detailing the methods of torture employed. There is also a small chest of valuables, all of which were taken from the executed, as detailed in the log. Throwing the wealth in the Pit will clear the tortured spirits there, putting them at rest. This will give them access to the Relic of Death Gifts.
The Pit: The final resting place of those deemed unimportant by the matriarch. No more than a large pit reaching hundreds of feet into the ground that the bodies of criminals and the lower class were flung into after their bodies were stripped of valuables (organs, marrow etc).
The Tomb of Galitt: This huge sprawling structure houses the bodies of those who did not survive the ritual, and those who were willing sacrifices for it. This was also used before and after the ritual as a site for tombs of important individuals (Kings, heroes, lords etc.), but was massively expanded on decree of Evalith, the last matriarch, as her first action after the ritual.
A large structure stands at the center of the city, seeming to be newly repaired, and standing out because of this. On the south side, facing the ravine is a large doorway, sculpted with stone and spiderweb. In the mouth of the door stand two Spiral Centurions. These sentries attack any intruders. Inside this structure is a number of Xill warriors, who will join the battle on the third round of battle (unless they kite away). The structure leads the the second layer of the city. Inside this layer, are much more intricate housing, built of various geometric shapes. It is much smaller, and contains these places of interest:
The Inverted Tower: A mage tower, inverted and built into the ground, reaching into all of the lower levels. On the door is a lock spell (dc28) thievery or dispel level 4.
The Silo: Contained the cities supply of food and water. Also seems to have contained fungal farms, which had long since taken over the entire Silo. Now is only dust and dead spores, in a jungle of long since decayed fungus. The mold is black, and although it has been dormant for millennia, is quick to reclaim life inside some lungs. The silo has not been used, or even approached for thousands of years, aside from one pair of footprints maybe a month old at most.
The Hatchery: Where the eggs from the matriarch were deposited. Had been repurposed into some sort of negative energy well since, and contains wraiths. On tables in various places are the broken bodies of mostly destroyed Xill, and tubes leading from the well of negative energy (which used to house eggs) to the tables they lie on.
The Broken Bank: Seems to have contained the cities wealth, coins and some magical treasures. This place seems to have been stripped free, and only the writing indicates what was there. In the coin vault there are a few thin gold coins with the imprint of a spider on one side, and four intersecting lines on the other. Loot: Black coins with spiders pressed into them. The press is present behind a large door inside the vault. The coins are made of heavily oxidized silver.
The Altar of the Matriarch: This serves as a place of worship to the Xill Matriarch, which has been deified. It has a huge statue of the matriarch made with incredible detail, carver out of some sort of black rock. It seems to now sit in disrepair, but on its back sits a pair of angelic wings, recently constructed. Behind the statue are the stairs to the royal chambers, and the royal treasury beneath.
The Balance of Truth: Xill library, and school. Ordered into open and forbidden knowledge. This library connects to the Inverted Tower, and where they connect is where the spell books, rituals, and books of magical knowledge are stored. Most of the books in the library are too rotten for use, and searching for anything useful can take hours or days, but many hidden treasures lie in this library (uncommon-rare spells and rituals etc.).
The Royal Chambers: The stairs down finally lead to a massive hall, 60 ft to the ceiling, supported by extravagant pillars adorned with carvings of matriarchs past, and their deeds - one pillar per matriarch. In this room, giant guardian Xill, bred specifically for defending the queen, will be seen lying dead on the ground. 10 or so huge beetle like monsters, 15 ft tall. In the chamber itself lies the matriarch, resembling a massive insectile Lamia. It will seem mindless, but in the room is a winged lich, that will turn and attack. During the battle, it seems to command the matriarch, which will swat at them with its tail, and summon in more xill (the big ones from outside) until the lich or her is defeated. The lich will seem to recognize the party, exclaiming "Ah you've brought me my masters shard, have you? How very nice of you. Hand it over, and I shall allow you to serve him in life, and not just in death." When they attack, he will attempt to dominate Al (or whoever has the shard at that time). If/when that fails, he will become angry and full on attack. If he feels threatened, he will attempt to heightened dimension door out, and flee. Behind the throne is the entrance to the Royal Vaults. This contains high level magical items.

Geography

A rift that was opened by an earthquake around the time of the Return of Magic, The Open Grave serves as an entrance to the ruins of the city of Erebus. The entrance is difficult to find, and viciously guarded by the cursed denizens of the city. The valley itself is mostly obscured by forest, hidden deep within The Agari Jungle.

Fauna & Flora

Xill , Xill spiders.

Natural Resources

Bones.

Alternative Name(s)

Erebus

Type

Gorge / Rift