There's a museum above the souvenir shop at Fort Siloso. It showcase the history of both the surrenders of the British to the Japanese and then the Japanese to the British during World War II.
When the Japanese invaded Singapore, they moved their headquarters from Malaysia to Ford Factory in Singapore. It is in this Board Room where the surrender documents were signed. The Board Room remains intact in Ford Factory but the table at which both the British and Japanese delegations sat is now in the Australian War Museum in Canberra, Australia. The seven teak chairs were moved to the Surrender Chambers in Sentosa where a replica of the event is displayed.
The above and below photos are wax figures which show the Japanese surrending to the British when they lost the war.
You can read more about the history of the surrenders from infopedia and mindef.