capriccio with ruins of the roman forum

An Architectural Capriccio of the Roman Forum with Philosophers and Soldiers among Ancient Ruins, including the Arch of Janus Quadrifrons, the Sarcophagus of Santa Constanza, the Farnese Hercules and the Cincinnatus. 1745-50.

Giovanni Paolo Panini. Italian 1692-1765. oil/canvas.

Matthias Withoos - Capriccio of the Roman Forum with Arch of Constantine and Coliseum - 

oil on canvas,  98.1 cm x 135.4 cm

In painting, a capriccio, in older English works often anglicized as “caprice”, means especially an architectural fantasy, placing together buildings, archaeological ruins 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 (1676-1730) but its best-known proponent was the artist Giovanni Paolo Pannini (1691-1765). This style was extended in the 1740s by Canaletto in his etched vedute ideali, and works by Piranesi and his imitators.