Valley of Death
The Valley of Death (VoD) is located in the heart of the Direlands north of the Obsidian Plains. The area is very difficult to navigate due to the closely spaced ridges. Bounded roughly between 55W and 75W, and 30S and 45S. Special high level creatures spawn here that are both high xp and drop Granite Keys and Marble Keys that open loot chests that randomly spawn in VoD. The keys are givable and must be made usable first with lockpick skill.
How to get there
The Obsidian Rim portal at the drop on Singularity Caul drops you at a Lifestone on the southern edge of VoD.
There is a retired portal that some people still have a tie to and can summon that drops deep in VoD at 36.7S 66.2W.
Creatures
There are also statues called Shadowy Statue of the Hopeslayer. These statues can appear where creatures normally spawn. Use the statue to spawn two Void Knights and 2 Raven Augurs. When killed, these have a chance of dropping a Small Shadow Statue of the Hopeslayer. Collect three and turn them in to Sarkin Killcrane in Wai Jhou for experience.
Rare Spawns
Hammer of the Fallen - Fallen Crystal Shard Mace of the Fallen - Fallen Drudge Atlatl of the Fallen - Fallen Grievver Eye of the Fallen - Fallen Lugian Staff of the Fallen - Fallen Crystal Shard Blade of the Fallen - Fallen Tumerok