Bukit Timah Nature Reserve is pure primary rainforest. Believed to be as old as 1 million years, it's the only place on the island with vegetation that exists exactly as it was before the British settled here. The park is more than 160 hectares (405 acres) of soaring canopy teeming with mammals and birds and a lush undergrowth with more bugs, butterflies, and reptiles than you can shake a vine at. Here you can see more than 700 plant species, many of which are exotic ferns, plus mammals like long-tailed macaques, squirrels, and lemurs. There's a visitor center and four well-marked paths, one of which leads to Singapore's highest point. At 163m (535 ft.) above sea level, don't expect a nosebleed, but some of the scenic views of the island are really nice. Also at Bukit Timah is Hindhede Quarry, which filled up with water at some point, so you can take a dip and cool off during your hike. The National Parks Board gives free guided tours on the third Saturday of the month at around 9:25am; call tel. 65/6554-5127 to register.