Brent has probably the largest district right now, with all land draining into the Pacific Ocean (with the exception of Japan proper), Southeast Asia, Australia, Oceania, and the Great Basin (Nevada/Utah). I’ve written one story in Thailand, will probably write one in Australia (unless I move the mermaids closer), one in Hong Kong, Seattle, and Zion. Still not sure what to do about South America, unless a certain space pirate wants to add more nazca lines on a whim.
"Kitto daijoubu da yo." - Sakura Kinomoto