Kids at Keystone love the Snow Fort at the top of Dercum Mountain. It is perched at 11,640 feet in altitude, and surrounded by blue and green cruiser runs. Play in the maze, sit on the Kidtopia throne, slide down the slide, or climb the snowy towers. It's the perfect winter playground on your ski vacation.

The big attraction is the snow castle. It takes about ten days to build it with four men working around the clock. The walls are 15 feet high, and the fort is about 40 by 60 feet. Keystone's Justine Chellel says kids and adults are in awe of the massive fort. "The kids go nuts. They can climb, play, and slide all over the fort. It's a pleasure to walk by and hear them laugh."

This is the second year of the Keystone Kidtopia Snow Fort. The big castle is all dependent on the weather, too. Keystone hopes to open it by Christmas.

The A51 Terrain Park offers a bit more daring adventures. The park has its own chairlift, making it easier for you to spend the day on rails, jumps, jibs and in the Super Pipe. You'll find features for every level. It is also Colorado's only night park.

Tubing is also available at Keystone this winter, at Adventure Point, which is at the summit of Dercum Mountain. The park has four tubing lanes. Snow biking and slopecycle also are available. The tubing hill is expected to open Nov. 24, and stay open through April 10.

Keystone is now open for the season.

Call 800-468-5004 for more information.