Menegroth is the underground city ruled by Thingol in J.R.R. Tolkien’s The Silmarillion.
Menegroth, whose name means “The Thousand Caves,” was the hidden capital of the Sindarin realm of Doriath in Beleriand. It was built in natural caverns beside the River Esgalduin, with the help of the Dwarves of Belegost. The city’s halls, bridges, pillars, and carved chambers were designed to resemble a forest, reflecting the influence of Thingol’s queen, Melian.
Thingol, also called Elu Thingol, was the King of Doriath, while Melian was a Maia whose power helped protect the realm with the Girdle of Melian. Menegroth is often confused with other famous underground places: Gondolin was a concealed Elven city built in the Encircling Mountains, Khazad-dûm was a Dwarven mansion in the Misty Mountains, and Nargothrond was Finrod’s hidden fortress.