What kind of building can be called a landmark building?

According to my personal understanding, landmark buildings are landmarks first. When the name of that building is mentioned, everyone can directly think of its geographical location, such as the Paris Tower. There are also designs and appreciation of buildings with positive appearance, which can conform to the public aesthetic, such as Suzhou gardens; At the same time, it should also reflect its advanced architectural technology, such as Sydney Opera House; Or it bears a heavy sense of history, which makes people step on the long river of history every step in the building, such as the Forbidden City. Wait, it can be regarded as a landmark building.