There is a certain invigorating quality to mountain air. It’s thinner, of course, but there’s also a coolness and crispness to it, and frequently a whiff of pine or juniper, too. Mountain air is the quintessential fresh air, and you can’t help but savor big gulps of it.
Ocean air is special as well. It’s got that salty tang to it, and also a faint (and sometimes not so faint) odor of rotting seaweed that we associate with the shoreline. And, because you are by definition at sea level, it’s a heady, oxygen-rich mixture.
So, which is better? That’s an impossibly tough call, but if I were forced to choose I’d probably go with the ocean air. I know one thing for sure, though — either beats city air, or indoor air.