In painting, a capriccio means especially an architectural fantasy, placing together buildings, archaeological remains and other architectural elements in fictional and often fantastical combinations, perhaps with staffage of figures. It fits under the more general term of landscape painting. It may also be used of other types of work with an element of fantasy. This genre was perfected by Marco Ricci but its best-known proponent was the artist Giovanni Paolo Pannini. This style was extended in the 1740s by Canaletto in his etched vedute ideale, and works by Piranesi and his imitators.
 
Bron: en.wikipedia.org