Sleepy Pulau Ubin was once a hotbed of rowdy gang activity in pre-war Singapore.
Initiation ceremonies by secret societies such as Sin Ghee Hin would take place on its shores.
This is one of several little-known facts uncovered by the National Heritage Board as part of its efforts to document the history of the 10.2 sq km, boomerang-shaped island in the northeastern corner of Singapore.
A team from the board, headed by group director of policy Alvin Tan, spent the last five months scouring academic texts, newspaper articles and conducting interviews with some of the island's 38 remaining residents to add to existing literature.
Mr Tan said publications about the island tend to focus on the island's flora and fauna and marine life. "Not a lot of research has been done on the lives of the people here, the occupations they held and how the land was used," he said.
He added that Pulau Ubin is worth documenting and preserving because it is the "last real kampung in Singapore".
There are plans to compile the information from the fact-finding exercise into an e-book and make it available to schools and heritage groups.
The island hit the headlines in April this year after a notice by the Housing Board led to confusion among islanders that 22 households would be evicted for the development of an "adventure park".
But the Government has since clarified that there are no plans for the time being to further develop the island, which is to be kept in a "rustic state for as long as possible".
Beyond the research effort, the board also launched a virtual tour of the island's main hub as part of its Walking Through Heritage series yesterday, while cooking classes organised by the Malay Heritage Centreat a Malay kampung house on the island will take place over the coming weeks.
By December, a documentary on Ubin's boat operators will also be uploaded on to the board's YouTube channel.
The video will be the final episode of the board's second season of Heritage In Episodes - a series of short documentaries aimed at connecting with the younger generation through social media.
The team's research further delved into detailing heritage sites such as the island's jetty, which was built by the Japanese during World War II, Singapore's oldest community centre and the Bin Kiang School, which was set up in 1952 and demolished in 2000.
Other interesting facts uncovered include how granite from the island was used in the construction of Fort Canning, Pearl's Hill Reservoir and the Horsburgh Lighthouse on Pedra Branca.
Islanders such as Mr Kit Kau Chye, 65, a boat operator and chairman of the Changi Point Ferry Association, said the island is worth documenting and conserving.
"Through these materials, I hope Singaporeans and other visitors will get to learn more about the island's rich history and make a visit here," he said.