The Great Wall of China (begun c. 214 B.C.), designed specifically as a defense against nomadic tribes, has large watchtowers that could be called buildings.
The Eiffel Tower is a 19th century iron lattice tower located on the Champ de Mars in Paris that has become both a global icon of France and one of the most recognizable structures in the world.
The Kentucky State Capitol is located in Frankfort and is the seat of the three branches (executive, legislative, judicial) of the state government of the Commonwealth of Kentucky. The building is listed on the National Register of Historic Places.