Hampstead Wetlands Park
Time Out says
While The Oval is bustling with the brunch crowd, next to it is the tranquil Hampstead Wetlands Park. Though just a small pocket of green in the somewhat industrial area, the former marshland area has seen been spruced up so that it looks like a lush English garden with a pond – complete with lily pads – now.
Though there are observatory decks and railings (so you don't fall over!), the area has retained its rustic element and is not as 'polished' as other parks. There is a short trail loop you can take which will take you through the forested area and by the waterside. You can easily explore the place under 30 minutes but keep the peace – it's a favourite haunt for birdwatchers in Singapore.