This one-room temple designed in Classical and ancient Corinthian style originally served as a spiritual center but was later transformed into, and consecrated as, a Catholic Church. Even today it is considered one of the greatest and most important religious buildings in the world. The construction of this structure is simple yet nonetheless complex. The front portico, boasting 24 Egyptian-style columns rising from Corinthian bases (capitals), gazes out on a small piazza della Rotonda. Large bronze doors open to a great circular room, above which rests a semi-hemispheric dome made out of solid concrete. Various recessed semicircular and rectangular apses are situated around the chamber wall, separated from the dome by a pair of monolithic columns.
The most interesting and distinctive feature of the Pantheon, of course, is the unglazed oculus (round opening) at the top of the dome, through which sunlight illuminates the porphyry, granite, and yellow-marbled walls and floor, shifting from sunrise till sunset so that one can determine the time of day simply by the position of the sunrays being cast inward. The Pantheon is open everyday except Christmas Day, New Years Day, and May 1. Admission is free, and bus rides are available. If unique spiritual places are an interest, this will be a fascinating experience.