Tour an elegant mansion. Hike (or ski or snowshoe) past waterfalls. Go horseback riding (or take a sleigh trip). You can do all of this, and more, at Castle in the Clouds, a mountaintop estate with incredible views and a full slate of activities, starting with a tour of the Arts and Crafts-style Lucknow Mansion, where the 1910s and 1920s come alive. The mansion, state-of-the-art in its day, features vacuum and housewide phone systems as well as vintage clothing and furnishings. And, you can tour the basement to see how the servants lived. Outside are gardens, a pond where kids can feed the leaping rainbow trout, hiking and skiing trails past waterfalls and a restaurant with panoramic views.