The Zoo - L4 In The Necklace

At the L4 point is a cluster of asteroids, all of them Builder-graviformed, and connected by loops to the River. Each asteroid contains from three to twelve distinct and separate self-sustaining ecologies, apparently imported by the Builders as curiosities. These asteroids are collectively called the Zoo, and this location is a mecca for tourism. Some of the ecologies are topped by films to keep in fliers, while others are open to the Necklace’s air. Over time, a few films have degenerated, allowing the fliers access to the greater Necklace, but Rasi and Altisherpa Rangers maintain the structural integrity of the films, and repair any tears that occur.