Ready to go waaay off the beaten path? Sure, you like to find the cafe that only locals know, or the hidden beach that you get all to yourself, but what about one-of-a-kind lodging? You could stay in a hotel...or you can book your next vacation in an Australian treehouse, a Balinese spa or even a yellow submarine. We've rounded up 6 of the most amazing rentals from Booking.com. And yes, there's a yellow sub on this list, plus it's big enough to fit a band and your friends all aboard (plus the ones who live next door).