Malta is blessed with a number of diverse coastlines, which makes it a haven for beach bums. The stunning Blue Lagoon is made up of a number of sea caverns that surround the breathtakingly turquoise bay.
On Russia’s Kamchatka Peninsula, fire and ice meet to form an otherworldly underground. Located on a slope of the peninsula’s Mutnovsky volcano, the cave’s stream is fed by volcanic hot springs. Sunlight filters through thinning glacial ice above