While Sumatra may be best known for the earthquake that hit off its coast on Boxing Day 2004 (and led to devastating tsunamis in the region), it is also famous for it amazing plants, beautiful scenery and the enticing mix of people who both visit and live on the island. There are more than 52 languages spoken on this island, approximately the size of France.
Foreigners come to Sumatra for two main reasons though: research and adventure. Travelers look for a night of clubs and dancing will head to Bali, but those looking to climb volcanoes or study orangutans come here.
Outside the northern city of Berastagi, Gunung Sibayak is Indonesia's most accessible volcano—you'll just need a good pair of walking boots, an extra layer of warm clothing, a map, a hiking companion and/or a guide. It isn't recommended to make the five-hour hike alone for safety's sake; if you're alone, hire a guide. You should be able to find one for 100,000 to 150,000 (around $10US). Set out early, it gets hot at the equator. Be sure to bring along some extra water and take the route that is most suitable for your interests and abilities.
Orang-Utan Feeding Centre
Just north of the volcano, Bukit Lawang is one of the best places to meet and/or study the native orangutans. Founded in 1973, the center was set up to preserve the diminishing number of apes, their numbers rapidly decreasing due mostly to hunting. Laws have changed, but the center continues to provide necessary medical care, rehabilitation and research. Visitors are welcome and are able to feed some of the orangutans directly (around 8:30a.m. and 3:00p.m.). If you're interested in venturing into the adjoining Gunung Leuser National Park, you'll have to get a permit (which can be a bit difficult).
Bordering on the equator, Maninjau Lake (Danau Maninjau) fills a volcanic crater and retains the paradisical beauty that has been lost in many touristed area. It's a long, winding journey out from Bukittinggi, but for a vacation from your vacation this is nirvana. A smattering of bungalows that can be rented circle the lake and provide a serenity that is often sought and rarely found.
Strange Plants & Cool Animals
The jungles of Sumatra have not yet been decimated and many native plants and animals continue , giving a glimpse at life that is rare outside of Indonesia. You can take treks through the jungles at Gunung Leuser National Park to see amazing pitcher plants and the noxious 'corpse flower.' Or head south to see rhinos and sea turtles at Bukit Barisan Selatan National Park.
For more information on planning a trip to Sumatra, check out Lonely Planet's Indonesia guide.