What is the main characteristic of a prostyle plan?

A prostyle plan is primarily characterized by the presence of a prominent porch supported by columns. This architectural style typically features these columns that create a grand entrance, emphasizing the façade and providing a sense of formality and elegance to the structure. The porch often leads into the main body of the building, which is especially common in classical architecture, where it serves not only as a transition space but also as a significant visual element that defines the building's character.

This focus on the porch and columns is fundamental to understanding prostyle architecture, particularly in ancient Greek and Roman structures, where such features symbolize civic pride and architectural sophistication. The interplay between the columns and the porch helps to engage visitors and sets a tone of importance for the building it adorns.