Galápagos
The regulated one
Sea lions, penguins and cool-water reef inside a strictly regulated national park.
The Galápagos is not a carefree beach trip and this catalog will not describe it as one: it is a tightly regulated national park, where a park entry fee is collected on arrival, many sites can only be visited with a licensed naturalist guide, and you reach the islands by flying from mainland Ecuador to one of the archipelago's two airports. It is also one of the few places on earth where you can snorkel beside sea lions and Galápagos penguins. The water runs cool on the Humboldt current, so exposure protection is normal rather than optional.