Located 8.5 kilometres from Eugi and 9 kilometres from the French border in the Pyrenean pass of Urkiaga, hidden among the beech trees of the forest of Quinto Real lie the ruins of the munitions factory of Eugi. This monumental complex covers 10,000 m2 and includes an old village which was once home to 500 people. This splendid 18th-century construction only retains its outer structure. The arches over the river Arga are the best conserved part. Nowadays, the ruins of the Royal Munitions Factory of Eugi maintain the essence of their structure and some of their arches and walls can be seen below the undergrowth in the shadow of the beech trees of Quinto Real. It is a good example of 18th-century industrial architecture.