Rising from the muddy fields on the Mekong riverbank in Laos, a lotus tops a casino in a sprawling city that analysts decry as a center for cybercrime.

Shabby, mismatched facades — including an Iberian-style plaza replete with a church tower, turrets and statues — stand alongside high-rise shells.

The Golden Triangle Special Economic Zone (GTSEZ) is the most prominent of more than 90 such areas established across the Mekong region in recent years, often offering people reduced taxes or government regulation.