Keeping with the theme of outdoor stuff moving indoors for year round enjoyment (these indoor waterparks will wet you up), we decided to check out indoor ski slopes. These things are feats of engineering magic and usually result in some pretty unique architecture. It's a relatively recent trend, and as its popularity increases, bigger and better ones pop up. The image above is a proposed indoor slope in Sweden, which would be around 450 feet tall. It's nothing new for ski resorts to produce extra snow and powder, but moving the entire thing inside for year-round snow and winter-related things is ballsy. Salute.

By Marc Yearsley