Level of difficulty: Easy
The Green Corridor trail technically spans 26km, that is, if you travel down the whole corridor from Tanjong Pagar Railway Station to Woodlands Train Checkpoint.
But I am not so ambitious, so I opt for an easier route that takes me from Commonwealth Avenue, a short walk from Buona Vista MRT Station, to Rail Mall.
I set out for my run on a cloudy Saturday afternoon, starting underneath a viaduct along Commonwealth Avenue.
It can be tricky to find this viaduct, so head to the carpark at Block 44 Holland Drive. From there, look for a metallic-looking staircase that takes you underneath the viaduct. There, you can find vibrant street art on the walls.
If you are lucky, you might spot an artist or two in the process of creating a new work . This stretch is known as the Rail Corridor Art Space, an authorised space for street art.
Moving northwards, I follow the trail, which is relatively flat and thus suitable for beginners.
The picturesque corridor, which is flanked by secondary forest in parts, is a welcome change from running on roads and past buildings.
There is a distinct kampung feel on the trail.
I squeal when I see a squirrel traversing a power line that cuts across the sky above me.
Trail Running Singapore member Yati Juwahi, 34, tells me when I ask her for some advice on trail running: "The same trail is never the same every day - there are weather changes, for example. You have to be prepared."
I realise she is right. As it had rained on the morning of my run, I find myself having fun jumping over puddles.
Running down the green trail of the Rail Corridor also carries with it unshakeable historic significance.
Though the railway tracks were removed in 2011, there are some preserved tracks which serve as reminders of the railway.
Here, I could not help but walk on the track, trying to maintain my balance while traversing it on tippy-toes.
The route also takes me past the quaint Bukit Timah Railway Station, where I spot some teenagers taking selfies.
And then there are the two iconic black trestle bridges - one at Upper Bukit Timah and the other near Rail Mall. It is hard not to be awed by these stately structures, which for me, are photo opportunities to be shared on Instagram later.
It is no wonder that the three- year-old Green Corridor Run is a popular fixture on the running calender here.
The 10.5km-long run, which takes runners from Tanjong Pagar Railway Station to Bukit Timah Railway Station, attracted more than 7,000 participants in March.
But on a normal day, the trail is not crowded. Sure, there are other hikers, runners and cyclists, but there is a shared spirit of adventure among us, as if we are all privy to a sweet secret.
This spot may not exactly be a secret, but tucked away from the hustle and bustle of the city, I feel less like I am running and more like I am coming home to nature.