geothermal active zone hverir near myvatn lake and hiking poles in iceland, resembling martian red planet landscape, at summer and

active area attraction boiling bubbles colorful crater destination equipment eruption force formation fumarole gears geothermal hiking holiday hot hverir iceland icelandic landscape magical martian mountain mud myvatn namaskard nature outdoor people poles remote rough sightseeing smoke soil steam sticks sulfur thermal tools tourist trail travel valve vapor vent volcanic volcano zone