Deep down: Photographer Amy Hinkle shot the spectacular images in January while on a week-long expedition to the caves of the Aquismon region in Mexico
Climbers at the bottom of the Golondrinas cave. The cave floor which is the size of three football pitches, is covered in millipedes, insects, snakes, and scorpions
Stunning scene: The view from the bottom of Huasteca cave, 225ft below the surface
Exploring: People inside the Cepillos cave .After travelling down some people build tents at the bottom and stay the night in the sinkhole
Pose for a photo: Photographer Amy Hinkle inside the Cepillos cave
Don't look down: Amy Hinkle seconds before rappeling into Golondrinas
Film: The Fellowship proceeds with caution in the Mines of Moria, in this scene from The Lord of the Rings: The Fellowship of the Ring. The Mexican caves have a similar quality to the film
Depths: The cave is 300 metres deep - there is a narrow continuation which leads through several steps up to 512 metre depth
