Two 1.8m-high walls, on either side of the road, slope upwards into the Labrador Nature Reserve. Occasionally, rays of sunlight break through the foliage and dance across their red-brick surfaces.
Joggers and other park users hardly pay them attention as they pass through. But the structures, remnants from 1886, tell a story of maritime and colonial history.
The walls once led to Fort Pasir Panjang, also known as Labrador Battery, which was guarded by a heavy iron portcullis - a latticed grille typically used in mediaeval fortifications.
Before reaching the gate, there was a stream that had to be traversed. Infantrymen would use a 3m drawbridge to get in.
The gateway was one of many military structures designed to help defend the western route into Keppel Harbour from piracy and naval invasions. But these installations failed to keep the Japanese army from taking the island in 1942.
The fort is one of 23 sites that are part of a new heritage guided tour of Labrador and Alexandra to mark the 75th anniversary of the fall of Singapore on Feb 15 that year.
The tour is the fourth permanent guided tour organised by civic group My Community and covers five areas: nature, military, maritime, industrial and public housing history and heritage.
It is likely the only regular and official tour of the often-overlooked area, said president Kwek Li Yong.
Speaking to The Straits Times, Mr Kwek said: "The tour aims to memorialise the fall of Singapore in our collective memory... We hope that it can serve as a vivid reminder of the past where younger generations of Singaporeans can understand the legacies of war.
"The tour also provides an in-depth context on how the British defended the naval outpost in Singapore and a vivid experience for participants to understand the devastating consequences of World War II on the British forces and ordinary villagers."
It is also one of the group's most intensive tours as it will take about four hours and require participants to traverse four hills across the rolling southern landscape.
Other sites include the 1930 Berlayer Beacon, which indicates the left of Keppel Harbour as seen from the sea; and a replica of the "Long Ya Men" granite rock formation, also known as the Dragon Teeth's Gate, which was used 600 years ago by the great Chinese explorer Admiral Zheng He as a navigational marker when he sailed by Temasek.
Several 20th century bungalows in Alexandra Park - a former military estate - will also be opened to tour participants. Mr Kwek described it as a rare chance to walk through the historic buildings.
Among them is the only art deco bungalow in the estate which was built by the Public Works Department in 1933.
Artist Plum Ovelgonne, 47, a tenant of the house in Canterbury Road, said she is opening up her place as she is "keen to help with heritage".
She moved to Singapore with her family from the Netherlands about three years ago. She said: "We love Alexandra Park, the historic houses and the beautiful greenery that overlooks the valley."
Guides will also take visitors through the Alexandra industrial estate, which had been designed by the British to generate employment and reduce reliance on entrepot trade. The tour takes place every second and fourth Saturday of the month, and runs from 8.30am to 12.30pm. The public can go to www.myqueenstown.eventbrite.sg to register for it.