A few years back, my sister and I decided to take our families to Flagstaff for Spring Break so that we could see the Grand Canyon. We rented a house in Flagstaff that would fit everyone, and on our first night there, I posted a picture. Somebody on Facebook replied and told me that we had to go see the Flagstaff Lava Tube while we were in the area, and I am so glad they did. Even though the Grand Canyon is absolutely amazing, I think going to this lava tube was truly the highlight of our trip. Since then, anytime anyone we know is in the area, I always…