Singapore Botanic Garden is a 74- hectare (183- acre). It is the only botanic garden in the world that opens from 5 a.m. to 12 midnight every single day of the year, and does not charge an admission fee, except for the National Orchid Garden . The garden is bordered by Holland Road and Napier Road to the south, Cluny Road to the east, Tyersall Avenue and Cluny Park Road to the west and Bukit Timah Road to the North. The linear distance between the northern and southern ends is around 2.5 km (1.6 mi). In December 2012, an application for it to be listed as a UNESCO World Heritage Site was
made.
National Orchid Garden is the main attraction within the Botanic Garden. Located on the mid-western side of the Garden, the hilly three-hectare site has a collection of more than 1,000 species and 2,000 hybrids of orchids.
The Singapore Botanic Gardens has a small tropical rainforest of around six hectares in size, which is older than the gardens themselves. The rainforest and its bigger cousin at the Bukit Timah Nature Reserve are located within the Singapore’s city limits. Singapore is one of the only two major cities with a tropical rainforest within its city limits, the other being Tijuca Forest in Rio de Janeiro .