Although I didn't want to take time from exploring the many wonderful trails teaming with wildlife in the Everglades I was glad I took this 1 1/2 hour tour. So much history,. some of which, I lived through.. They were scary and dangerous tines for all of the inhabitants of our planet, including us "more advanced" ones. Real got to see how the men performing this task lived and worked in the "hole in the donut".