The bus hums steadily along winding mountain roads, cutting through verdant cattle fields and mist-cloaked highlands as it ascends toward Poás Volcano. This active stratovolcano, one of Costa Rica's most accessible volcanic craters, beckons with a roiling acid lagoon that shifts colors under a volatile sky. Standing at Poás’s rim, the crisp air carries the scent of sulfur and wet earth, while clouds swirl obediently around the crater, occasionally clearing to reveal the cobalt-blue crater lake—an elemental spectacle shaped by millennia of geologic upheaval.