Negrón Tunnel

The Negrón Tunnel is an automotive tunnel which connects the provinces of Asturias and León in Northern Spain. The tunnel is long and reaches a height of.The tunnel is in the toll highway AP-66, which is part of the Autovía A-66, one of the longest highways in Spain.HistoryInitially, the first roadway was planned with a cost of 19.5m pesetas, but it rose to 70m due to several unexpected problems in the terrain. This one was started in 1976 and gave work to 1,300 people during several years. The first of the two projected tunnels was opened in 1983 and worked provisionally as a single carriageway road.Works ended in 1997, with the opening of the second roadway in June 1997, which had length and costed 7.443m pesetas.Since its opening, the AP-66 is the main connection between Asturias and León.