Nan Curunír, or the wizard's vale, is located around the Isengard waypoint, and is home to the many orcs and other creatures that Saruman has bred into his service. The "capital" of the biome is Isengard. When you first enter the biome you get the achievement "Vale of the Wizard".
It is suggested that good players do not go into this biome unless they are well prepared. There are lots of Uruk-Hai and there Wargs about, and Isengard snaga (some atop wargs), although they are not as much problem. Dunlendings also will spawn herem as well as their warrior counterparts. Aside from that, the land is generally crawling with evil.
The biome also contains one of the first major structures in the mod, The Circle Of Isengard, a wall around Nan Curunir with a gate at the road.
Warg Pits - Pits of Uruk Brick accessed by a ladder that contain Uruks, a chest and some Uruk Wargs.
Ruined Houses - Burnt down houses that contain chests, furnaces, and crafting tables. These come in 2 varieties: ruined and burnt.
Stone Ruins - Stone Ruins are few stone bricks spawn randomly on the ground. They contain no chest.
Blasted land - Patches of Wasted Land (Before Beta 26 appearing in Rohan Uruk Highlands only, with soul sand instead blocks).
Mobs
Uruk-Hai - orcs bred with Goblin-men by Saruman to be stronger, smarter, and resistant to sunlight. They are strong and heavily armed, and wield scimitars, spears, daggers, battleaxes, warhammers, and more. The Uruks are a deadly force against good players.
Uruk-Hai Crossbowers - Uruk-Hai armed with crossbows, which deal significant damage.
Uruk-Hai Berserkers - Uruk-Hai that are larger, stronger, and harder to kill than their counterparts.
Uruk-Hai Sappers - Uruk-Hai armed with deadly Orc Bombs, which were invented by Saruman. After the bomb is used, they attack with a scimitar.
Uruk Wargs (can be ridden) - evil wolves allied with the Uruk-hai. They can be ridden by Uruks, attack on their own, or carry bombs (the latter is only true if a player hired the Wargs, or during an invasion).
Uruk-Hai Chieftains - traders and leaders of the fearsome Uruk-hai from whom you can hire all of the above.
Uruk-Hai Traders - traders who spawn in Uruk Camps and sell you items for silver coins.
Dunlendings - wild and somewhat primitive men who hate the men ofRohan, whom they call 'Strawheads', for driving them from the plains. They carry wooden, stone, or, rarely, iron weapons, and can also hold clubs, hoes, tridents, or other tools of labor. They give easy alignment for Rohan (and others) as they are easy to kill.
Isengard Snagae - the "peasants" of Isengard will spawn here, some atop wargs.
Vegetation
The valley mainly consists of patches of grass and dirt. Large boulders are also found, some of which consist of waste blocks. Trees that spawn here are: oak (normal and large), spruce and an occassional willow tree. Many charred and dead oak and spruce trees bear witness of the destructive nature of the lands inhabitants. Fire has burnt grass and dirt into useless waste.