This concept home built into the side of a cliff is just about the coolest thing ever. Designed by OPA the concrete cube structure will be built into the side of a cliff that looks out towards the Aegean Sea. The coolest part? the fact that is also has a rooftop infinity pool that from above appears to blend perfectly into the ocean. It also lets natural light flood through the building, turning the concrete walls and interior into a submerged hideout worthy of a bond villain.