Mansions and residences such as mansions built on flat ground during the medieval period and modern times do not include castles, but residences or mansions with towers which were built similarly to castles are regarded as castles.
中世・近世に、平地に築かれた館や館造りの陣屋等は城には含まないものの城郭構の陣屋や館、少しでも城に近づけて造られたものは、城とすることがある。