This instance is entered through a HUGE door on the upper level of the Frostfell Wonderland Village at ( 104, -4, -1150 ) /waypoint 104, -4, -1150. You'll see a couple of goblins near tables by the door. See the image to the right.
If you are in the Frostfell Wonderland Village and click on the door before you pick up a quest, nothing will happen! You will get text that says, "Shhh...it's a secret," instead.
The heroic version has tougher monsters and requires more strategy. Keep any of the seemingly "fluff" weapons from the solo version of the adventure quest; it is needed to complete the heroic version well.
This article refers to events, personae and activities only present in-game during the annual Frostfell celebration. Frostfell comes to Norrath each year from (roughly) the second week of December to the first week of January.