Aaron Green, FAIA suggested the concept and site for the underground COUNTY JAIL, completed in 1994, to complement Wright’s original building’s design. The jail is embedded into the hillside at the end of the Hall of Justice wing. This location makes it possible to transport prisoners into the court areas through a tunnel. (There is a scale model of his plan on the fourth floor of the Administration Building outside the branch library.)The Marin County Jail “encompasses 222 cells (accommodating 363 beds) as well as common areas and oversight spaces. The building is as much as 60 feet below the hill?s surface. California law dictates that prisoners have a right to discern between night and day, so skylights provide abundant natural light. Designed not to compete with the appearance of the Marin County Civic Center, Frank Lloyd Wright?s last design project, the jail literally disappears into the natural environment. Designers at DMJM incorporated other ecologically sound details such as recycling gray water.” (SubsurfaceBuildings.com)