|Inhabitants||Rohirrim refugees, later Dwarves|
|Events||Battle of Helm's Deep|
The Glittering Caves were located behind Helm's Deep under the three peaks of the Thrihyrne in the northwestern arm of the White Mountains. The Glittering Caves extended deep under the mountains, with many passages, stairs, halls, and chambers. The floors were sandy and the ceilings were high, domed vaults. The walls were polished stone set with gems and crystals and veins of ore.
The entrance to the caves was behind the Deeping Wall in a narrow gorge that could be defended long against an onslaught, making them an ideal refuge location.
Gimli called the Glittering Caves one of the marvels of the Northern World. Reportedly, Legolas was left speechless after visiting them, one of the few times that a dwarf has bested an elf with words.
Aglarond was explored during the Second Age by Númenóreans, although it is unclear exactly when and by whom. Later, after the founding of Rohan it was used as a storage space and refuge for Rohirrim who used the Hornburg.
 War of the Ring
During the Battle of the Hornburg on 3-4 March, T.A. 3019, many of the women, children, and elderly people of the Westfold took refuge in the Glittering Caves. Livestock and food were stored there as well.
Some Orcs crept through a culvert in the Deeping Wall and entered the gorge but were killed or driven back by the defenders. Then the Deeping Wall was breached by an explosive device and the Enemy forces entered the Deep. Many of the Rohirrim including Éomer were driven back to the Glittering Caves, and with them was Gimli.
 As a Dwarven colony
When Gimli Elf-friend was held up in the caves, he was amazed by their beauty. After the War of the Ring he brought from Erebor part of Durin's Folk and founded a colony in the caves, becoming the first Lord of the Glittering Caves. The Dwarves of the Glittering Caves carefully tended the stone walls and opened new ways and chambers and hung lamps that filled the caverns with light. The Glittering Caves became one of the most important realms of the Dwarves at the beginning of the Fourth Age.
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Two Towers, "The Road to Isengard"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Of the Rings of Power and the Third Age",p. 291
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Two Towers, "Helm's Deep"
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Return of the King, "Many Partings"
- ↑ J.R.R. Tolkien, The Lord of the Rings, Appendix A, "Durin's Folk"
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The Battles of the Fords of Isen", Appendix (ii)
- ↑ J.R.R. Tolkien; Humphrey Carpenter, Christopher Tolkien (eds.), The Letters of J.R.R. Tolkien, Letter 321, (dated 4 February 1971)