Singapore's tourism also aims to be environmentally friendly, maintaining natural and heritage conservation programs. Along with this, it also has one of the world's lowest crime rates. Transport in Singapore is quite extensive, and is regarded as one of the best overall, making most areas on the island easily accessible. The Mass Rapid Transit (MRT) system is one such example of transport infrastructure.
The Orchard Road district, which is contains multi-storey shopping centres and hotels, can be considered the center of shopping and tourism in Singapore. Other popular tourist attractions include the Singapore Zoo, River Safari and Night Safari. The Singapore Zoo has embraced the open zoo concept whereby animals are kept in enclosures, separated from visitors by hidden dry or wet moats, instead of caging the animals, and the River Safari has 300 species of animals, including numerous endangered species.
A night view of the Supertrees at Gardens by the BayJurong Bird Park is another zoological garden centred on birds, which is dedicated towards exposing the public to as much species and varieties of birds from around the world as possible, including a flock of one thousand flamingos. The tourist island of Sentosa, which attracts 19 million visitors in 2011, is located in the south of Singapore, consisting of about 20–30 landmarks, such as Fort Siloso, which was built as a fortress to defend against the Japanese during World War II.
Singapore promotes itself as a medical tourism hub, with about 200,000 foreigners seeking medical care there each year. Singapore medical services aim to serve at least one million foreign patients annually and generate US$3 billion in revenue. In 2015, Lonely Planet and The New York Times listed Singapore as their top and 6th best world destination to visit respectively.