This is taking Adventure Travel to the very edge: the huge fire crater in Turkmenistan. It’s not volcanic, but probably a Soviet-era gas-drilling error. Just getting a visa is an adventure and a half, and forget about travel insurance cover. Check out this Science Alert report http://www.sciencealert.com/the-door-to-hell-is-in-turkmenistan-and-is-the-size-of-a-football-field?utm_source=ScienceAlert+-+Daily+Email+Updates&utm_campaign=bbc0f28b47-MAILCHIMP_EMAIL_CAMPAIGN&utm_medium=email&utm_term=0_fe5632fb09-bbc0f28b47-365553829

“It’s said that camel spiders, seduced by its warmth, will approach and plummet to their deaths like a scene out of an apocalyptic, arachnid movie…”