Cave of as Choias Nature · A Pobra do Brollón, Terra de Lemos, Lugo The Cova das Choias, at the place of Biduedo, parish of Óutara, is a naturally formed cave dominated by cavities opened by human hands to extract iron ore, mainly in the 16th and 17th centuries. It takes its name from the red-billed choughs that nested near its mouth. It has three levels running for about one hundred and twenty metres, a width exceeding twenty metres and vaults over thirty metres high; the middle level is the most interesting for its whimsical rock formations and the colour contrasts produced by the oxidation of iron, from intense green to various shades of ochre. About 75 metres from the entrance a gallery opens that connects with the lower level, from which five further galleries branch off, only one with an exit to the outside. Photo: 4migosd xavitooh (CC BY-SA 4.0) What to see and do in A Pobra do Brollón