Tree Top Town: More than a few, actually. Eliéra is – in a self-reinforcing cyclical way – cooler, wetter, and much more forested than, say, Earth, silviculture takes an equal place with agriculture, and one could put forward a not unreasonable thesis that eldrae are natural forest-dwellers in the same sense that humans are natural plains-dwellers.
So in quite a few places – Veranthyr and Cimoníë being the first two that leap to mind – people possessed of tall and large trees, often with convenient hollows, decided that they would be perfect places to live in. For a start, it saves trying to clear the forest, first. For a second, in the early days of civilization, it helps to live somewhere the nastier predators aren’t and the fruit and the sunlight and so forth conveniently are. Et cetera.
It’s not Bamboo Technology, though. The people who live here are as fond of shiny things as the rest of their culture, and just because it’s made of wood and in/on the treetops doesn’t mean it’s not as full of modcons as any house anywhere else.