Watch: Wall Of 850-Year-Old Jaisalmer Fort Collapses

Jaipur: A new video shows a portion of the exterior wall of the famous Jaisalmer Fort in Rajasthan collapse on Thursday, revealing the extent to which the 850-year-old monument is under threat.

The video of one of India's best known heritage sites was sent to NDTV by a conservation architect. The wall caved while it was under repair by the Archaeological Survey of India.

A major accident was averted as those working on the fort's restoration were away at lunch and there were no tourists in the vicinity and so fortunately, no one was injured, said Chandra Prakash, a resident of the fort.

The cause for the collapse is said to be leaking sewer lines, which result in excessive water weakening the foundation of the 12th century fort. But this is not a new problem. The Jaisalmer fort, called the only "living fort" in the world was built to support 500 people. Today, the number of residents and tourists can go up to 10,000.

There are several small boutique hotels and houses inside the fort, now fitted with modern toilets, flushes and shower systems, which pull in unprecedented volumes of water. As a result, the old drainage system of the fort, built for an arid soil and desert climate has for long been collapsing.

Conservationists argue that this is an old issue and should have been addressed a long time ago, especially given the funds and multiple agencies that have been working for the protection of this magnificent monument.

The Jaisalmer fort is an ASI protected monument and was declared a UNESCO world heritage site in 2013. It has got grants from the World Monument Fund and several other conservation agencies.

But this collapse of the wall, the third in ten years, seems to indicate that these conservation efforts are failing.