The Descent

Twenty-one separate cave sets were built for the film. These were carefully reused with different camera angles, set dressing and lighting to suggest a nearly endless collection of interconnected tunnels and caverns. For realism, the makers often limited the lighting of the sets to light sources that the protagonists brought with them, such as flashlights, helmet lights and light sticks.

All of the spines in the various bone piles throughout the movie have the spines intact and the inter vertebral disks still present in the spines. Inter vertebral disks, however, are cartilage, not bone, and would have decayed (especially given that there is no clothing, hair, or fur in the bone piles, meaning that the bones are quite old). The spine segments should be scattered and in pieces, not in long segments.

The creature's snarling sound can be heard at the end of the credits.

SPOILER: The endings of the US and UK versions differ. In the end, Sarah wakes up at the bottom of the cave, crawls out, and makes her way back to the car. When she is driving away, she pulls over and vomits, and when she leans back into the car, she is startled by the ghost of Juno sitting in the passenger seat. The US version cuts to the credits here. In the UK version, this apparition causes Sarah to wake up for real at the bottom of the cave, revealing her escape to be just a dream. She then has a vision of her daughter's birthday cake, which we see is just her torch. The camera backs out, the voices of the creatures can be heard again and are increasing in strength as they are closing in on her, and the movie ends. This ending was considered "too dark" for US audiences.

Edited into The Descent: Deleted and Extended Scenes (2006)