Several years ago, as a friend and I were walking past, a church guide told us she was just about to start a tour of their catacombs and invited us to join. When we hesitated, she told us this is a very special place, one of the few sites in the world with naturally-preserved mummies. We decided to take the tour and learned that between 1631 and 1784, about 4,000 people were buried here. While not all were mummified, the reason for the preservation was that in certain locations the crypt had just the right combination of temperature, humidity and air flow. It was quite an interesting, moving experience. I guess, no matter what you desire, it pays to be in the right place at the right time.