There is an enjoyable book, written by someone who has explored these and (many) other deep places in the world. I think I saw it posted on HN originally. Book

There is an enjoyable book, written by someone who has explored these and (many) other deep places in the world. I think I saw it posted on HN originally. Book name: Underground Author: Will hunt amazon search url: https://www.amazon.com/s?k=under+ground+will+hunt https://www.amazon.com/s?k=under+ground+will+hunt