If you're going to have a door as elaborate and beautiful as this, you'd better have a damned impressive house for it to open into. Otherwise, it's all disappointment once you cross the threshold.
This door, created by Matharoo Associates for a diamond merchant in India, is flat-out crazy. It's 17 feet tall, five and a half feet wide, and is made up of 40 sections of Burmese teak. The door uses a counterweight, 80 ball bearings and 160 pulleys to create the incredible effect of reconfiguring into a sinusoidal curve when you push on any one section. Amazing.