The term '30s Architecture Style' refers to the Art Deco style of architecture which was popular in the 1930s. Art Deco is a style of visual arts, architecture and design that first appeared in France in the 1920s and quickly spread around the world. It is characterized by its use of bold geometric shapes, bright colors, and lavish ornamentation. The term 'Deco' is often used as a shorthand for this style.