Medan

Medan is Indonesia's biggest city outside Java and the doorway to North Sumatra's two stars: orangutans at Bukit Lawang and the vast crater lake of Toba. It suits adventurous travellers on a second or third Indonesia trip, not first-timers doing Bali. Give the city half a day, then head out.

• Trek to see semi-wild orangutans in Gunung Leuser National Park (Bukit Lawang) — day treks with a licensed guide run roughly Rp600,000-900,000 ($35-$50)
• Two-day trip to Lake Toba and Samosir Island, the Batak heartland — stay a night on the island rather than rushing it as a day trip
• Maimun Palace and the black-domed Great Mosque in the city, both quick stops you can cover in one morning
• Eat your way through Medan's famous food streets — try soto Medan, durian pancakes and the city's Chinese-Indonesian kopitiam breakfasts

Medan's Kualanamu airport has direct flights from Singapore and Kuala Lumpur in about an hour, and from Jakarta in a little over 2 hours. An airport train reaches the city centre in around 30 minutes — take it, because Medan traffic rivals Jakarta's.

Treat Medan as a hub, not a destination. A sensible loop is one night in the city, two nights at Bukit Lawang for the trek, then two at Lake Toba before flying out. It pairs poorly with a beach holiday — if this trip is your first look at Indonesia, do Bali and Java first and save Sumatra for the return visit.