hikers exploring the active etna volcano on lipari with mount vesuvius and the tyrrhenian sea in the backdrop

39aph39 active activity adventure ash backdrop boiling cliff coast colorful cracked crater danger dramatic environment erupting etna exploding exploration exploring explosive extreme fire flow flowing fumes gas geology geothermal glowing group heat hikers hill hills italy landscape landscapes lava lipari mist mount mountain natural nature object outdoors overlooking phenomenon plain pools power rock rugged s scenery sea smog steam strength surrounded temperature terrain travel trekking treks tyrrhenian vesuvius views villages volcanic volcano