The answer is: It is the “Interior of the Dome of St. Peter’s Basilica at The Vatican”. This church was built in the Late Renaissance period and finished in the Baroque period. It is a wonderful example of Italian Architecture and Design.
Donato Bramante was first asked to prepare plans for the construction of St. Peter’s Cathedral. His complex designs for creating a dome with four identical radiating arms forming a Greek cross began in 1506. Later revisions to change the concept to the Latin cross came out of the Vatican’s concern for Roman paganism and trying to reference more Christian symbology were applied, however parts of Bramate’s work are still visible. It is also important to note in 1546 Michelangelo’s plans by adding several bays to the nave were applied along with later the work of Bernini and also Carlo Maderno showing even more influence of the Latin Cross into the floor plan for this cathedral. The point to note is how many important and revolutionary architects and artists assisted in the creation and renovation of such a building. After witnessing this first hand you can start to understand the magnitude of all these great minds in one place.