Bel Marin Keys, California

From Wikipedia

Bel Marin Keys is an affluent water-front community located east of the Novato City Limits in Marin County, California. The community is an unincorporated area of the county with approximately 700 homes. Most of the homes sit on one of the many beautiful lagoons, although some are on the Novato Creek. All of the lagoons have access to San Pablo and San Francisco bays through the navigational locks.

Bel Marin Keys was a planned community built between the late 1950's and late 1980's. Phases 1 thru 4 were completed, but phase 5 was never built and instead the land is in the process of being converted back into wetlands, which were dried out in the early 1900's for farm land. Phase 5 would have roughly doubled the size of Bel Marin Keys had it been built.