The Panthéon

From 1790 to 1889, the Panthéon was the highest point in Paris. Then the Eiffel Tower showed up and stole the crown. 

Look up at that dome and consider this: Louis XV promised to rebuild the old church of Sainte-Geneviève after recovering from illness in 1744. When the bill arrived, the treasury was empty. The solution? Sell millions of lottery tickets. France literally gambled its way to this monument.

Architect Soufflot designed it as a Greek cross with a spectacular triple dome, and it was completed in 1790. Almost immediately, it stopped being a church and became a temple to France's greatest minds. Voltaire and Rousseau were among the first inside. Two giants of the Enlightenment who publicly despised each other in life now rest directly across from one another in the crypt. 

Oh, and there is something here involving a pendulum and the rotation of the Earth. We will tell you that story next.