In Lenidel, the principal nation on the planet Trillia, most cities are spread through a large forest and park. The city of Annanna has two million busy inhabitants, with perhaps three aircraft visible at once. Pedestrians and cyclists proceed along The Pathway Of The Beautiful Blossoms And The Bridge That Arches Like A Note Of Music.
Number 1337 on The Pathway Of The Beautiful Blossoms And The Bridge That Arches Like A Note Of Music has, over an otherwise doorless entrance, spicy-smelling, sunlight-trapping flowering vines. The interior has a wooden floor, stools and an intricately faceted rock crystal. The occupant, Witweet, reads poetry and addresses a visitor with endearments, offering Lapsang Souchong and sweet cakes. There is occasional trade with the Polesotechnic League and the Trillians, like the Merseians, have bought tea. Trillians can sell arts and crafts but, lacking the means to buy modern technology, are developing it themselves. I do not think that Trillia will need to join the Supermetals Company.
Around number 1337 are colorful flowers, red tree trunks, bright fluttering wings and the distant sound of The Waterfall That Rings Like Glass Bells. An armed Terran whose vocalizer transforms his speech into song knows that to omit honorifics and circumlocutions without apology is to issue a deadly insult.
Avalon appears in three short stories and one novel whereas Trillia is mentioned and described in just this single short story, "A Little Knowledge." Nevertheless, it is yet another colorful alien environment imagined in detail by Poul Anderson.