Mumbai, Aug 25 (IANS): A slice of history in the form of a British-era underground bunker, discovered in the sprawling Maharashtra Raj Bhavan premises three years ago, shall soon be thrown open for public viewing around Diwali.

On August 18, President Ram Nath Kovind unveiled what is India's first-ever 'underground museum' developed within the estimated century-old bunker, spread across over 15,000 square feet with 13 rooms and a 20-feet tall majestic gate.

"Everything had been buried for several decades till Governor C.V. Rao was informed of the bunker by a retiring employee. The Governor ordered it to be opened and excavated anbd later ordered it to be converted into an interactive museum for posterity," a senior Raj Bhavan official told IANS.

Though the exact historical credentials of the bunker complex are being explored by the historians and experts, it may have been constructed to prepare for any eventuality during World War I and II.

For some unknown reasons, it was probably shut down sometime in the 1950s till it was rediscovered in August 2016.

A portion of the historic bunker lies buried below the lawns and another part below the Jal Bhushan, which is the official residence and workplace of the Governor.

"After careful digging, we found that for over a century, it had suffered considerable wear and tear due to seepage from the overhead lawns, rains and moistures of the Arabian Sea, which is barely a few metres away. The Governor desired that it should be conserved without compromising the safety of Jal Bhushan or the surrounding structures," the official explained.

The entrance of the bunker resembles a fort and inside, the bunker had rooms named such as 'Shell Store', 'Gun Shell', 'Cartridge Store', 'Shell Lift', 'Pump', 'Central Artillery Store', 'Workshop' etc., implying that it was full of life after it was built and had served as an important weapons and ammunitions storehouse.

What stumped officials was the presence of a proper drainage system underground with sufficient inlets for fresh air and light, indicating that considerable care had gone into it construction to accommodate the (then) occupants safely for prolonged periods in case of a war.

"Since there may have been huge quantities of explosives stored here, it had built-in water pipelines to reach the entire bunker in addition to a 10-feet wide ventilation duct for air and sunlight to pass through," said the official.

"The discovery of the bunker created huge excitement among the people in Maharashtra and elsewhere in the country. There were many constraints in opening it. Now we have conserved the century-old complex and created a 'virtual reality-assisted museum' that will engage people with our glorious past," Governor Rao had said during the unveiling of the museum.

Adding to the beauty of the bunker was the discovery of two gigantic cannons, each weighing 22 tonnes, from the Raj Bhavan complex in 2018.

They were discovered during a tree plantation drive in November 2018, dug out from the earth around 25 metres apart, astounding the Raj Bhavan's 250-plus staffers and officials.

Dating back to over a century, or the pre-WW-I era, the canons are 4.7 metres long and 1.15 metres in diameter. They have been restored to their original glory and have been placed prominently near the Jal Vihar, the regal banquet hall of the Raj Bhavan.

The 'underground bunker museum' will have virtual reality-based holographic techniques on the themes of canon firing experience, the history of the Raj Bhavan complex, a glimpse of the majestic forts of Maharashtra, dioramas of cannons and soldiers and optical illusions of the bunker and cannons to thrill the visitors.

Though the Government House located in Parel, which was the seat of power in Mumbai, came into existence way back in 1665, the present Raj Bhavan started developing after 1880 on the rocky Malabar Hill, promontory hugged by the Arabian Sea on three sides.

From a modest single office-cum-residence of the then Governor, over the years it has developed into one of the most beautiful and picturesque complexes in the city, spread over 50 acres, comprising a 1.5 km long forest and a private beach.

Now, the Raj Bhavan officials are keeping their fingers crossed on what other hidden or buried secrets will emerge in future from the massive complex.