The Vielha tunnel (Aranese: Tunèl de Vielha, Catalan and Spanish: Túnel de Viella) is a road tunnel in Spain, connecting Vielha, the capital of the Aran valley, with the Alta Ribagorça comarca. It is part of the N-230 road and consists of two parallel tunnels. The older one, named Alfonso XIII Tunnel in honour of Spanish king Alfonso XIII, was opened in 1948 and became the longest road tunnel in the world, with a length of 5240 metres, until 1964, when the Great St Bernard Tunnel was inaugurated.
The new tunnel, named Juan Carlos I Tunnel in honour of the Spanish king Juan Carlos I, is 5,230 m (3.25 mi) long and was opened in 2007 with two lanes heading southbound and one lane northbound. The old tunnel is nowadays used as an emergency exit and since July 2011, also as a lane used by trucks which carry flammable or other types of hazardous loads.[1]