The much awaited excavation work of Rohtang Tunnel began today. The National Advisory Council Chairperson, Mrs. Sonia Gandhi laid the foundation stone of the 8.8 kilometer horse shoe shaped tunnel at the southern portal, 25 kilometers from Manali in Himachal Pradesh. The Defence Minister Mr. A.K. Antony was also present on the occasion besides several dignitaries. The Border Roads Organisation spokesperson Col. Rahul Trivedi said the northern portal of the tunnel will open in the Kellong valley of Himachal Pradesh leading to Leh.