Wander one of the City of Joy's urban slums after dark, visiting families whose lives have been changed by solar lights provided by Bangalore-based social enterprise Pollinate Energy. The lights also reduce carbon emissions from kerosene lamps. See urbanadventures.com.

"SEA CAMPING", KOH LAOLIANG

Koh Laoliang is that rare thing in Thailand: an island national park (in Trang province, south of Krabi) in a marine park with a pristine beach and no resorts, daytrippers or noisy longtails. Instead, guests stay in spacious tents right on the beach. See laoliangisland.com.

HIKE THE GREAT WALL, CHINA

Escape the hustle of China's capital with Beijing Hikers, a family-owned operator that started as a walking club for locals and expats and runs day treks on seldom-visited parts of the Great Wall, and clean-up hikes every year. See beijinghikers.com.

GREEN SCHOOL, BALI

Inspiring a love of nature is what this revolutionary international school in Ubud is all about. Take a tour of the all-bamboo Green School or neighbouring Green Village; there are also workshops on building with bamboo, permaculture and other sustainable arts. See greenschool.org greenvillagebali.com.

WANGDUE ECO LODGE, BHUTAN

This family-owned eco lodge in central Bhutan, which opened in 2015 as part of a Low Carbon Tourism Project, is the epitome of sustainable tourism. Its four cottages are built to resemble traditional farmhouses, the food is all organic and grown onsite, and activities include Bhutanese cooking classes and cultural hikes. See bhutanecolodge.com.

KAYAKING KARST ISLANDS, PALAWAN

Sea kayaking is one of the most sustainable ways to travel and Palawan, the third largest island in the Philippines, is one of the best places to do it thanks to its spectacular karst islands, pristine coral reefs and remote beaches to camp on. See southernseaventures.com.

SONG SAA PRIVATE ISLAND, CAMBODIA

Luxury eco-resorts aren't uniquely Asian, but Song Saa was Cambodia's first and is sublimely special. Built on twin islands a world away from seedy Sihanoukville, its 27 eco-chic villas, restaurant and spa overlook Cambodia's first marine reserve, established by the Australian owners. See songsaa.com.

LEOPARD SAFARIS, SRI LANKA

Sri Lanka takes the safari experience to another level by offering not just wildlife such as leopards (Yala National Park has the highest density of leopards in the world), but also Buddhist temples and tea plantations, beaches and blue whales. See leopardsafaris.com.

MOUNTAIN BIKING MUSTANG, NEPAL

One of the last bastions of Tibetan Buddhist culture, Upper Mustang in northern Nepal is best explored by mountain bike, particularly now there's a (rough) road to Lo Manthang, once a five-day hike from the nearest airstrip, and a new 17-day trip there led by Australian adventurer Huw Kingston. See worldexpeditions.com.

SAVING SEA TURTLES, THE MALDIVES

Extend your next stay in the dreamy Maldives by doing conservation work with turtles and manta rays for Seamarc, a consultancy of Maldivian and international marine biologists, in their research centre or on a liveaboard dive boat. See seamarc.com/volunteers.