Achasan Trails - Goddess of Granite

Trails such as:

Hell's Gates - tight and twisty,
Condescending - featuring the world-famous (in Korea) three series "Litmus test" for the newbies and virgins. Think STEEP, bumpy, gnarley, granite sections, then a long, bumpy funky, steep, rocky lovely single track that will just have you grinning at the bottom.
Middle Finger - apt name and a trail that is simply designed for freeriders, Similar to Condescending but tighter and steeper. Like a granite, bumpy, luge run on wheels
Yellow Brick Road - wonderful rocky speedy fun but, these days, a main hiking trail available only early morning/early evening,
Spankinator or Spanky for short - similar to Yellow Brick Road and same hiker issues as Yellow Brick Road. Both of these are excellent night runs with enough reflected light from the city on overcast evenings
Two-trench - high level fast crosscountry descent, with, funnily enough, two military trenches that you rail across. Bony in places.
Warmup trail crosscountry descent, Xc sort of trail
Yaksu, same but also an effective push up from the bottom of Rocky Dog, Purgatory and Hell's Gates. Three wonderfully twisty, trails through trees and over bumpy rocks.
Stinky Crack and Fight Club - both shorter but relatively bumpy, nasty trails. Yummy.

Let me be perfectly frank with you - this mt. ain't for the fainthearted. Get a solid Filthy attitude, don the shining armour and prepare to do battle. The Goddess of Granite only lets the big boys take her. The rest of the riff-raff she'll eat up, rip skin off and wantonly flay before she discards you for another plaything. One thing we've learnt well in 7 years of having this mt. is that she plays hard. Scars and vivid memories to prove it. A fine line between beautiful pain and beautiful pleasure. More of a free riders mountain or a XC boy with excellent technical, skills. If you are a XC guy, no worries, you can always walk the tricky bits. You just have to buy the beer at the bottom.

If there were two words about Achasan it would be "gnarley granite". Traction to die for on steeps and deeps where you really need it. Rockbumps and rockjumps all the way across her. Located right in center city (east) so pretty damn quick to access.