The Norwalk Islands are a chain of more than 25 islands amid partly submerged boulders, reefs and mudflats along a six-mile (10 km) stretch and mostly about a mile off the coast of Norwalk, Connecticut, and southwest Westport, Connecticut, in Long Island Sound. Among these islands, Chimon and Sheffield Islands are the largest.

In 1980 an investigation revealed that Chimon Island hosted the largest heronry in the Long Island Sound. Substantial conservation efforts have unfolded to protect the thousands of herons, egrets, and gulls that depended on the island. Wildlife like raccoon and deer have negatively impacted the heronry over the years, However, with ongoing management of the islands, it is hoped that the birds will continue to feed, rest, and nest there.