Indoor climbing gyms have exploded in Bangkok — world-class facilities at fraction of Western prices.
Bangkok's indoor climbing gym scene grew rapidly from 2015 — there are now 15+ facilities around the city ranging from basic walls to international competition-standard gyms.
Boulder Thailand (Lat Phrao), Bloc Climbing (multiple locations), Café Climb (Thonglor, good for beginners with coffee) — all offer day passes and equipment rental.
Day pass: 250–500 THB; equipment rental: 100–200 THB; far cheaper than equivalent facilities in Europe or North America.
All major gyms have introductory courses (500–800 THB for 2 hours including equipment) — Bangkok is an excellent place to try climbing for the first time.