“District” or “historic district” means a designated, geographically defined area, urban or rural, small or large, possessing a significant concentration, linkage or continuity of buildings, objects, sites and/or structures united by past events or aesthetically by plan or physical development that has been listed in the Bothell register of historic landmarks. (Ord. 2322 § 6, 2020; Ord. 2069 § 2 (Exh. B), 2011; Ord. 1635 § 1, 1996; Ord. 1258 § 1, 1987).