Some wonders aren’t found on land — they’re hiding just below the waves. Off the western coast of Thailand, in the balmy embrace of the Andaman Sea, there’s a scattering of islands that hold the keys to an underwater paradise. This isn’t just another tropical destination. This is the Similan Islands — a dreamscape of coral cathedrals, white sand crescents, and electric-blue waters.

On the sun-scorched southern coast of France, wedged between the bustle of Marseille and the calm of Cassis, lies a slice of wilderness that looks like it leapt out of a Mediterranean dream. Welcome to Parc National des Calanques, a national park where jagged limestone cliffs plunge into turquoise coves so clear, they look Photoshopped.