Here are the best online marketplaces for finding unique adventure trips in Asia, with what each is best for and a source so you can browse options directly.

1. GetYourGuide — Best for booking guided day trips, multi-day activities, and larger inventory across Asia (easy filters, lots of partner operators). (en.wikipedia.org)

2. Viator (Tripadvisor Experiences) — Best for huge selection, traveler reviews, and flexible cancellation options for day tours and excursions. (viator.com)

3. Klook — Asia-focused, mobile-first platform good for local adventures, attraction passes, and last‑minute bookings across East and Southeast Asia. (en.wikipedia.org)

4. KKday — Strong regional coverage and curated local experiences (especially Japan, Taiwan, SE Asia); good for niche/adventure activities and regional insider offerings. (forbes.com)

5. TourRadar — Best marketplace for booking multi‑day organized adventures, treks, overland trips and small‑group tour packages across Asia. (tourradar.com)

6. Airbnb Experiences — Great for unusual, locally hosted adventures (guides, hands‑on workshops, small-group outdoors experiences). Good when you want hyper-local, one-off activities. (airbnb.com)

7. G Adventures — Operator/marketplace focusing on small‑group, sustainable adventure trips (trekking, island hopping, active itineraries) across Asia. Good for longer, structured adventure trips. (globaljourneys.com)

8. Intrepid Travel — Another specialist operator for small‑group adventure travel and active itineraries (hiking, biking, cultural immersion) across Asian destinations. (intrepidtravel.com)

9. Traveloka Xperience / Trip.com / Rakuten Experiences — Regional superapps that bundle activities, transport and local services; useful if you’re already booking flights/hotels there and want integrated bookings. (Example: Traveloka Xperience for SE Asia.) (traveloka.com)

10. Aggregators (PlacePass and others) — Good when you want to search multiple platforms at once and compare price/availability for the same activity. (wanderprep.com)

Quick practical tips when booking:

• Use filters (duration, difficulty, group size, “adventure” or “active” tags) and read recent reviews to confirm operator quality. (justgonewandering.com)
• Compare the same tour on two sites — sometimes booking directly with the operator or via a regional platform (Klook/KKday) is cheaper. (justgonewandering.com)
• Check cancellation policy, what’s included (equipment, permits, transfers), and operator safety certification for higher‑risk activities (trekking, diving, climbing). (justgonewandering.com)

If you’d like, tell me which country, activity (trekking/rafting/caving/ice‑climbing/food/adrenaline sport), travel dates or budget and I can pick the top 3 specific listings and links to compare.