volcanic landscape of leirhnjukur, myvatn geothermal area in iceland

leirhnjukur geothermal landscape formation hverarond icelandic sulfurous volcanic colorful mountain iceland mineral geology natural outdoor tourism tourist volcano myvatn fields orange active barren crater europe spring hverir krafla nature people scenic sulfur travel black hills cloud field grass magma stone area lava soil clay hill land moss park rock view hot red sky