Nautilus Undersea Suite at The Poseidon Resort, Fiji. Normally I don't post stuff like this, but wow. this is officially my dream vacation spot. I could spend hours lying in bed watching the fish swim by!
Glass igloos in Finland to sleep under the northern lights. Hotel Kakslauttanen's Igloo Village in northern Lapland. Their 20 glass igloos have thermal panes that keep the digs warm and prevent frosting.