Refers to property owned by a public entity such as a national or local government, as opposed to private property (私有財産).
This park is city public property.
The management of public property is stipulated by law.
私有財産 means 'private property', owned by individuals or private entities, while 公有財産 is owned by public bodies.
国有財産 specifically refers to property owned by the national government, a subset of 公有財産 which includes local government property as well.
Compound of 公有 (こうゆう, 'publicly owned') and 財産 (ざいさん, 'property').