Old Town Hall, registered with the National Register of Historic Places as California No. 78000799, was built in 1907 as a joint Solano County and Vacaville City project to replace an old jail that had fallen into the creek below. It provided space for the city's hand-drawn fire hose cart, an upstairs council chamber with office rooms and a lavatory, and was regarded as the handsomest building in town, with crenulated roof corners and a bell tower. The building was lighted by electricity, heated by gas, and fitted with lead plumbing. Two steel cells held difficult prisoners, while a long rear room served as the walking room, or drunk tank, for ordinary drunks, hobos, and thieves, and there was a separate cell for ladies. Downstairs stood the town's first public water closet and the pull-rope used to ring the great fire bell in the tower above. Its walls, ceilings, and floors were made from 11 carloads of concrete reinforced by 10,000 feet of steel rods. It is said to be one of only two such stout buildings west of the Mississippi River. Over more than a century, this fireproof building has served as a jail, County Sheriff's Office, firehouse, courtroom, City Hall, Civil Defense Relay Station, Crisis Center, Art League office, and as the home of the Vacaville Heritage Council, the Solano County Genealogical Society, the Pena Adobe Office, and the Solano County Historical Society.