Ironically, the second-largest city in isolationist Kyonin is human-run – the only official point of entry into the kingdom for anyone not of pure elven blood. This busy trading town, famous for the yellow roofs on every building, is a bold elven experiment in peaceful co-existence. The elves study human behavior and trustworthiness in this controlled environment; the queen’s agents covertly scry and occasionally teleport in unannounced when they take issue with events there.
The elves have benefited more than anyone from the open economy, as Greengold is the only stable, legal market for elven magic and goods manufactured in Kyonin. Despite tight controls, Greengold is awash in money. A small but thoroughly cosmopolitan city, Greengold hosts diplomats, traders, and expatriates from every nation in the Inner Sea and beyond. Respected ambassadors to the queen can embark from there to the Kyonin interior if they meet official approval, and all civilized people are welcome to stay in Greengold as long as they can afford it.
To visitors, the town appears as a fairly normal human dock town, save for trees that grow in odd places. Ever since the horrified elves forbade humans from felling them (forcing them to import their lumber or harvest it from dead trees and blowdowns), it has been illegal to harm threes in town. Merchant-Mayor Selwyn Vanaidorl, a philosopher-turned-merchant from Taldor who claims to have small amounts of elven blood in his lineage, runs the city with a light touch and frequent meetings with elven nobility.
Sources: Pathfinder Companion Elves of Golarion