The Indian capital city of New Delhi has constructed a 2.85km tunnel, the largest in the country, as part of its ongoing metro rail project.
The tunnel, built under the Central Ridge, extends from Talkatora to Buddha Jayanti Park.
The tunnel has been built using the New Austrian Tunnelling Method of controlled blasting under the earth's surface.
It is part of Delhi Metro's 125km Phase II, of which 35km runs underground, and which is expected to be complete by the end of 2010.
The tunnel's completion leaves just 2km more of tunnelling work for Phase II.
Work is being implemented by the Delhi Metro Rail Corporation.