Each winter, Harbin, in northeast China, hosts the International Ice and Snow Sculpture Festival, featuring enormous buildings and sculptures constructed from blocks of ice carved from the nearby river. A fascinating 36-minute video details the stunning amount of logistics, creativity, and ingenuity that goes into building this ephemeral megacity (it exists for a mere two months).

(I once visited the Harbin ice festival in 2012 with my wife and friends. I remember being awed by the beauty and astounded by the scale—massive, though not yet the world’s largest ice and snow festival that it is today. I also recall it was bloody cold. I mean brutal.)