As I finish tying my boots and wrapping a bandana around my head, I notice that my hands are shaking. What have I gotten myself into? With backpacks full of snacks and water, and headlamps around our necks, my Couchsurfing host is taking his girlfriend and I on a night exploring the old mining tunnels underneath Paris. When he told me we were going to go visit the Catacombs, I had naively thought he meant the organized part tourists visit. Little did I know he had a plan of his own. Around 11 pm we drove to a fairly deserted part of town, climbed over a brick wall onto abandoned train tracks, walked down a tunnel and climbed through a tiny hole into the never-ending, multilevel, maze of tunnels under Paris. Immediately the darkness pressed upon us allowing only a few feet of visibility from our headlamps. When my guide turns a corner the sound of his footsteps quickly disappears so I hurry to stay as close as possible. The ground slopes and pitches so often it is impossible to tell how far underground we are and I repeatedly hit my head on the rocky ceiling. As my host had warned us, we followed his steps exactly. Why, you ask? Well, aside from my intense fear of getting lost, there were occasionally holes along the paths that drop into oblivion, and when dark water is coming up to your waist, well, you don't want to slip. After a few hours of walking, we climbed up through a hole in the wall to a room so small we had to crouch to fit. I found a stone to sit on...looked down...and realized I was sitting on a pile of human bones. Creepy hardly even begins to describe it. And then the science nerd inside of me came out as I started naming the bones surrounding me. And yet the night was only beginning. We settled to rest in a room were a rough castle was carved into the rock. My reality shifted seeing all of the candles and small figurines other adventurers had left there. How many people knew about this secret world? An undefined amount of time later, I started wondering if we'd have to backtrack to get out and then quickly realized I'd have no idea if we went the same way. Eventually we were led to a hole in the wall near the ground that we slithered through single file. It led to a circular, vertical tunnel with a ladder bolted to the side which we climbed up until finally we slid open the manhole cover onto a sleepy street and blinkingly stepped into the morning sunlight. It was 7:30 am and I felt as if I just walked out of a very realistic dream.