Mirkwood Corrupted

"'There lies the fastness of Southern Mirkwood', said Haldir. 'It is clad in a forest of dark fir, where the trees strive one against another and their branches rot and wither.'"

- The Fellowship of the Ring Mirkwood Corrupted is the vast majority of the Mirkwood forest, which is corrupted by the evil that dwells in the fortress of Dol Guldur. The Mirk-oak Trees are tall and dense; the grass is dark, and Mirkwood Spiders are plentiful. Be careful, some spiders are poisonous, and some have venom that gives you effects of slowness. Webs of Ungoliant can be found in the trees and on the ground, making navigation tricky. Ominous purple butterflies spawn here, but pose no threat, compared to the giant spiders that lurk under the trees. In rare occasions, Ruined Wood-elven Towers can be be found.

Upon entering Mirkwood Corrupted, you gain the achievement "Stay on the Path". Following this advice could pay off in the long run, as the path leads you to the uncorrupted portion of Mirkwood, known as the Woodland Realm.

Mirkwood Mountains
The Mirkwood Mountains spawn in Mirkwood Corrupted, and are located south of the Woodland Realm. This biome is just like normal Mirkwood Corrupted, except it is much more mountainous. This is not a hospitable region for anyone allied with the Elvenking of the Woodland Realm, because they can be attacked by Mirkwood Spiders, and can fall to their deaths off the cliffs that are common in this biome.

Mirkwood River
The rivers in Mirkwood are like normal rivers, except, like the rest of Mirkwood Corrupted, they are corrupted by Dol Guldur. If you step in these rivers, you receive effects of blindness, slowness, and mining fatigue. One river here represents the Forest River.

Structures
Only one structure spawns in the forests of Mirkwood Corrupted, and its occurrence is rare.
 * Ruined Wood-elven Towers- Once occupied by Elves of the Woodland Realm, these towers are now ruined, empty, and degraded. However, at the bottom there is a chest containing loot of many varieties. But be careful, there is no easy way out, as many dark things dwell in the depths of these towers...

Mobs
The only mobs that spawn here are Mirkwood Spiders.
 * Mirkwood Spider- These spiders were bred by the power in Dol Guldur, and released into the corrupted parts of Mirkwood. They are hostile to any enemies of Dol Guldur, so beware. These spiders can spawn in many different sizes, from huge to tiny. There are three types of Kirkwood Spiders; the black ones merely do damage, the green ones have a poisonous bite, and the blue ones give you effects of slowness.

Vegetation
Mirkwood has dark green grass. The trees here are all Mirk-oaks, which are tall, broad trees with large canopies. The tree coverage is so thick, that one could cross the forest on the treetops in most places.