Keystone in Summit County, Colorado, is a purpose-built ski resort close to the city of Denver with skiing on three inter-linked mountains. The US resort has a good range of terrain and some impressive scenery, with the Rocky Mountains as a backdrop.

Keystone is a lively, family friendly resort with excellent amenities and one of the biggest and best-designed terrain parks in North America.

Constructed in the 1970s by the Ralston Purina Company, the Keystone ski area is now owned by Vail Resorts. The resort has 22 lifts, including two gondolas, one express six-person ski lift and five high speed "Quads", and consists of three mountains named Dercum Mountain, North Peak, and the Outback.

One of the things Keystone is most famous for is its night skiing possibilities, with extensive, floodlit slopes open until 10pm. A51 Terrain Park is Keystone's largest night park and has witnessed significant investment and growth in recent years.

Keystone has some excellent tuition available for skiers of all ages and abilities, including group and private lessons on all possible terrains. The resort is also popular with snowboarders, with lessons and equipment hire readily available and a 'Superpipe'.

The resort has 2,870 acres (12 km²) of ski-able terrain and 3,128ft (953m) of vertical terrain, while the ski season runs from November to April.

Other snow-related activities available at Keystone include tubing, snowbiking and snowcycling, skating, snowshoe treks and toboggan rides. Dog sleigh, cross country skiing and snowmobiling trips of the area can also be arranged.

Keystone offers some excellent opportunities for children, with childcare and a nursery in the resort, Snowplay Programs for three-year-olds and upwards and a children's story hour. For older children, there are specially targeted lessons and ski school courses available.

Although Keystone does not have the history and unique scenery of some of the older European or US resorts, it provides a good value, hassle-free holiday destination, particularly for parents with children in tow, and some excellent skiing.

There are some excellent views available across the Rocky Mountains and the nightlife is varied, lively and friendly.

With a permanent population of just over 800, Keystone becomes very busy during the winter months and the bars fill up with chattering skiers. It is a lively resort, but can be pricey in some areas.

River Run provides clean and comfortable self-catering accommodation, a host of shops, bars and places to eat. Cheaper accommodation near Keystone is available in nearby Breckenridge and Frisco, with plenty of B&Bs and motels.

In the evening, Keystone has some excellent restaurants and eateries with a range of foods available, from fine dining to cafes and snacks. A number of venues provide online booking systems and skiers can choose from fondue, steak houses and seafood, amongst other options.

For those seeking things to do off piste, Keystone has a number of attractions, from its boutique store and golf courses to a local health spa, with a range of treatments on offer. A number of the bars schedule DJs and there are concerts and live music gigs on throughout the winter months. In summer, visitors can choose from mountain biking, hiking, fishing and mini golf.