The Blue Lake, a natural reservoir and one of three crater lakes at the top of Mt Gambier, an extinct volcano and town in the south east of the state, South Australia, Australia

Mt Ngauruhoe, 2291m, youngest of the three volcanoes in the Tongariro National Park, North Island, New Zealand

The three emerald lakes and volcano landscape of the Tongariro Alpine Crossing, Tongariro National Park, UNESCO World Heritage Site, North Island, New Zealand, Pacific

Three former volcanos, Roque de Agando, Degollada de Agando, Mirador de los Roques, La Gomera, Canary Islands, Spain, Europe

One of three crater lakes at the summit of Kelimutu volcano near Moni, soil chemical creates the unusual colours, island of Flores, Indonesia, Southeast Asia, Asia

Tiwu Ata Mbupu (Lake of Old People) one of three crater lakes on the summit of Mount Kelimutu on Flores island, Indonesia.

Sunrise over Tiwu Ko'o Fai Nuwa Muri, one of three crater lakes on the summit of Mount Kelimutu on Flores island, Indonesia.

Tiwu Ata Polo (Bewitched or Enchanted Lake) one of three crater lakes on the summit of Mt Kelimutu, Flores island, Indonesia.

Kids in Potato field on small farms near Volcanos National Park, Rwanda

Kids in Potato field on small farms near Volcanos National Park , Rwanda

Three Bells of Fira, Iconic blue-domed church and belfry with sea view, Catholic Church of Dormition, Firostefani, Santorini, Greece, Europe

Panorama, High Desert landscape, view of the Three Sisters volcano, Cascade Range, Oregon, USA