MBK is a large tourist mall in the center of Bangkok. The shopping centre offers tons of cheap goods to tourists and locals a like. Every wednesday night a local promoter puts on shows for free. Tons of spectactors line the sidewalk and hang out on the side of the BTS (the skytrain whose last station is at the mall) while nak muay go at it in the ring. It might not be Lumpinee but it has seen far more people.