A futuristic "space age rocket" was built in Seletar in 1969 - the same year astronauts from the Apollo 11 space flight landed on the moon.
The structure at Upper Seletar Reservoir, designed and built by the Public Works Department, was one of four lookout towers erected in Singapore in the 1960s and 70s.
The National Heritage Board (NHB) has started documentation efforts on the four towers as part of its bid to expand its database on Singapore's built heritage.
It said Seletar's 18m lookout tower is reflective of the "exploration fervour" of that era.
"It was when the interest in exploring space reached its zenith," said NHB researcher Ian Tan, 27.
"It features a very avant-garde and futuristic design, much like Seattle's Space Needle."
As well as the one overlooking the 1,093ha Upper Seletar Reservoir, there are other towers at Toa Payoh Gardens, Jurong Hill and the Chinese Garden.
Mr Alvin Tan, the board's group director of policy, said it plans to launch research projects on heritage infrastructure "on a regular basis".
So far, it has completed one on heritage bridges and plans to start another on roundabouts - such as Newton Circus and Serangoon Garden Circus - by June.
Mr Alvin Tan said its current project seeks to uncover architecturally and historically significant data on Singapore's lookout towers.
The aim is to then share the information with the public "as they enjoy the beautiful views", he added.
The towers functioned as diplomatic tools when newly independent Singapore forged relationships with other nations.
Dignitaries and royalty from around the world were taken to these vantage points to see Singapore's progress first-hand.
In the 1970s for instance, the seven-storey Jurong Hill Lookout Tower, which offers a panoramic view of the Jurong Industrial Estate, played host to Britain's Queen Elizabeth II, the former vice-president of the United States Spiro Agnew, and Deng Xiaoping, who was then Vice-Premier of China.
There, they would have seen the Republic's rapidly changing landscape and infrastructure - especially in areas such as housing, industry and recreation.
"Dignitaries were also brought up to see Singapore's development to help them decide if they wanted to invest here," said Mr Ian Tan.
Today, the Jurong Hill Lookout Tower is a popular spot for dating couples.
At its foot is the popular Hill Top Japanese Restaurant.
"People come here to dine because they enjoy the unblocked view of the sea which is unique in built-up Singapore," said its co-owner, Mrs M. Ong, 65.
The board is searching for old photos taken of and from these structures to supplement the information it has retrieved from government records, old news reports and photos from the National Archives of Singapore.
The project will culminate in a public talk on March 1 at the National Museum of Singapore.
Research findings and virtual tours of the four towers will also be uploaded to the NHB's website as part of its Walking Through Heritage initiative.
