The largest church in Christianity, Saint Peter's towers over Vatican City like the hand of God. Supposedly located upon the hallowed ground on which its namesake was crucified, construction on the Basilica di San Pietro began in 1506, and would last well into the following century. None other than Michelangelo, who would not live to see its completion, designed the Basilica's dome.

The interior of San Pietro Italy is a study in marble collection. It's everywhere you look - the finest example being Michelangelo's timeless Pieta, Mary's loss and sadness trapped behind plate glass. The church also contains 45 altars, including the papal altar by Bernini, and the Throne of St. Peter, whose feet you may kiss if you so desire. And that is only the main floor.

The dome of the building is the largest in the world, designed in homage to the Duomo in Florence. For a small fee, you can climb a spiral staircase to the church's apex and look out into the city. Even from 375 feet in the air, Rome is intimidating as it surrounds St. Peter's square - rolling out into the Alban hills before stretching into infinity. From this vantage point, the tip of San Pietro Italy, you can also see the papal apartments and the Vatican Gardens.

Down below, you can visit the grottoes of the Basilica di San Pietro, the final resting place of some of Catholicism's most famous leaders. Both ancient and recent popes can be found here behind gates and cool glass walls.

The Basilica di San Pietro, was birthed under less than glorious circumstances, however, inadvertently launching the Lutheran movement. After bribing the cardinals to ascend to the papacy, Julius II initiated construction of the church not for holy reasons, but because the tomb he had, Michelangelo design for him would not fit into the Constantinian Basilica. The construction required funds - which were garnered by the selling of indulgences (cash in trade for the pardoning of sins) across Europe. The selling of the afterlife angered a monk named Martin Luther, who used the exploitation to bring about the Reformation.

So, despite the church's plan to showcase San Pietro Italy as the symbol of the grandeur of God, it instead resulted in the fragmentation of Catholicism. But this hardly dampens the legacy of the church that helped redefine the word "opulent."