Singapore
Singapore is compact, clean-cut and almost impossible to get lost in. The East-West Line has a station at Changi Airport, and a contactless bank card tapped at the gate works as the ticket on trains and buses, so there is nothing to buy on arrival.
The city-state cannot offer far-flung day trips, but it packs the variety in close: the MRT reaches the Botanic Gardens, the hawker centers of Chinatown and Gardens by the Bay, the Sentosa Express monorail runs out to Sentosa, and a bumboat from Changi Point crosses to Pulau Ubin, a rustic island of quiet trails. A visitor who wants another country can ride a bus across the causeway into Johor Bahru.
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