The Glittering Caves, also called Aglarond, were the spectacular jewelled caverns that lay in the White Mountains behind Helm's Deep in Rohan. When Gimli Elf-friend was held up in the caves with Éomer and many other Men of Rohan during the Battle of the Hornburg, he was amazed by their beauty. After the War of the Ring he brought from Erebor part Durin's folk and founded a colony in the caves, becoming the first Lord of the Glittering Caves.
The Glittering Caves are one of very few locations in Tolkien's work that are associated with a real place. They were inspired by the Cheddar Gorge and Caves in the southern English county of Somerset.