"Ghost hunter" Charles Goh was trying to find the tomb of a Japanese naval officer at Mount Faber in 2005 when he stumbled on a century-old body of water that had vanished from the maps of modern Singapore.
Not that he knew it then.
"I was seeking out rarely explored, historical and haunted places to take tour groups to," said Mr Goh, 46, a specialised tour guide and co-founder of Asia Paranormal Investigators.
He thought it was a swimming pool, going by the remains of a diving board, and left it to continue his hunt for the 1943 tomb.
Separately, a team of National Heritage Board (NHB) researchers doing a topographical study of Singapore earlier this year spotted the reservoir in a 1905 Tanjong Pagar Dock Arbitration map.
Consulting other maps, they noticed how cartographers and planners later labelled it as a swimming pool in 1938. By 1958, just the contours of the water body were demarcated. In 2000, it was not even on the map.
This intrigued NHB assistant researcher John Kwok, 36. After ploughing through more than 50 maps and old newspaper articles, he headed to densely forested Mount Faber, past 350 Telok Blangah Road, to try to find it.
"I felt a rush after finding the reservoir which had long been forgotten by most people here and was not part of the public domain of information," he said.
The team then put together a documentary on the forgotten Keppel Hill Reservoir, which is about one-third the size of an Olympic-sized swimming pool and about 2m deep.
Since its launch on the board's site last Thursday, the documentary has been viewed more than 45,000 times. NHB's other YouTube videos usually get a thousand or so views on average.
The team's findings will be provided to Mr Goh, whom NHB has engaged to conduct free one- hour tours of the reservoir.
Members of the public can follow NHB's Facebook page to receive updates on tour dates. NHB said it has started sharing its findings with other government agencies, including the Urban Redevelopment Authority, National Parks Board and Singapore Land Authority. The land the reservoir sits on is zoned as park land.
Shopkeepers near the abandoned Keppel Hill Reservoir said dozens of people have visited the area since news of the discovery broke last week. The Straits Times saw signs of increased traffic when it visited the place yesterday. Litter was strewn around the site, and some tree branches had been hacked away.
Said Mr Kwok: "It's a beautiful, wonderful and peaceful pocket of space in Singapore... We urge the public to stay safe if they choose to explore the area and not to upset nature's balance."
This article was first published on September 23, 2014.
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