In Singapore, modernization has swept away the grungy opium dens, crowded back alleys and narrow portside streets, replacing them with spiffy high-rises and look-alike housing clusters. But no self-respecting former British colony would demolish its gardens and green spaces, and even in the midst of downtown's concrete jungle they offer respite for a weary traveler. Trees near St. Andrew's Cathedral have shaded these lawns for more than a century. Even along the mighty stretches of urban canyon, the city's showplace of commerce, flowers grow in tubs, palms edge the roadway and vines spill over concrete abutments.

But Singapore's more serious gardens are the places to go. Venture forth early in the day to see the 200 species of shrubs, flowers and trees in Singapore's Botanic Gardens, before the many fragrances blend into a sweet bouquet. The Botanical Gardens are planted with a Victorian sensibility, which makes sense, since they were established by British colonialists in 1859. But the gardens are more than a museum of plants spread over 74 acres. Research and experimentation are also sponsored here. The orchid section, opened in 1995, displays some 3,000 varieties.

Just a few blocks from the Botanical Gardens, on Orange Grove Road, are the gardens of the Shangri-La Hotel, nicknamed "Singapore's Other Botanic Gardens" because botanists at the two gardens trade specimens. Shangri-La's 15 acres are planted with more than 100 varieties of shrubs, flowers and trees, 133,000 royal palms, dwarf coconuts, durian and cashew trees, bird of paradise plants, spider lilies and dozens of other exotics. Most luxury hotels of this caliber don't let just anybody stroll their grounds, but the Shangri-La welcomes anyone genuinely interested in the plants.

You could visit Singapore's theme parks set in garden environments out in the suburbs--Jurong Bird Park, Singapore Zoo, the Night Safari, the Chinese and Japanese Gardens, Sentosa Island. But none of them is natural. The truly wild places, on the other hand, are on the main island. A Singapore native recommended McRitchie Reservoir and Bukit Timah Nature Reserve as the most natural areas on the main island.

With a faint photocopy map provided by a helpful guard at Bukit Timah, I loped off into the forest. Immediately I was in a jungle. Okay, a jungle with a path running through it. A jungle filled with trees so tall my neck cracked when I tried to look at their tops. That would be the meraga, a member of the coffee family, with what appeared to be long slots in the trunk. From a nameplate beside another tree, I learned that Pellacalyx saccardianus (membuluh) vines were growing up the trunk. They looked like huge snakes, the kind that drop out of trees and squeeze jaguars to death.

Most visitors stick to the short, paved routes near the visitor center, so I roamed the dirt and gravel path around the forest, alone. I didn't worry about safety; the only danger was my imagination, ripe with creatures that probably hadn't prowled Singapore in a century. So a couple of hours later, when I came upon a couple playing on a rope swing, hollering and laughing like Tarzan and Jane, I was actually glad to see them.

The Botanic Gardens, whose main gate is at the corner of Holland and Cluny roads, are open daily 5 a.m. to midnight; free admission. The orchid garden is open from 8:30 a.m. to 6 p.m. and admission is charged. The Shangri-La Hotel is at 22 Orchard Grove Rd.; tours of the gardens are offered Saturdays between 10 and 11 a.m. Bukit Timah Nature Reserve, 177 Hindhede Dr., is open daily, dawn to dusk; free admission. MacRitchie Reservoir, on Lornie Road near Thomson Road, is open daily, dawn to dusk; free admission.