Ryan Deboodt combines his love of caves, photography and drones in this amazing video of drone footage taken inside Hang Son Doong, the world’s largest known cave, in Vietnam.

The cave is over three miles long, 660′ high, and 490′ wide, and it has been estimated that an entire city block of 40-story buildings could fit within the caves main gallery.

For the drone footage, Ryan used a DJI Phantom 2 drone and a GoPro Hero 4 Black camera. You can see more of his drone and non-drone camera work at Ryan Deboodt Photography.