A Road That Never Opened: The Unfinished Port de Rat Tunnel in the Pyrenees
Set high in the Pyrenees mountain range, the Port de Rat Tunnel is an unfinished high-mountain tunnel that was intended to connect Andorra and France.

What was the tunnel supposed to bypass?
The tunnel was designed to bypass the international Port de Rat Pass, a high mountain crossing at an elevation of 2,372 m (7,782 ft) above sea level. It was planned to link the parish of Ordino in Andorra with the Ariège department in southern France.
Why was the project abandoned?
Although the project aimed to provide a direct connection between Andorra (at 2,370 m above sea level) and France (at 2,157 m), it was abandoned due to a lack of funds. The French government, unable to secure the necessary financing, backed down from the project. As a result, only the Andorran slope of the Pyrenees was drilled.
What remains of the tunnel today?
Today, what was meant to be a strategic tunnel has become little more than a cave, now serving as a tourist attraction within the ski resort of Vallnord.
What was the original vision for the project?
The tunnel was a joint project between both countries, initiated in the second half of the twentieth century. If completed, it would have revolutionized the local economy by allowing easier access for the thousands of French travelers who visit Andorra each year. However, only the initial excavation on the Andorran side was ever carried out, and the ambitious vision was left unfinished.
Pic&more info: http://www.ordino.ad/turisme/natura/Senderisme/camins-de-llarg-recorregut/el-port-del-rat