Hverfjall, a massive tephra crater formed about 2,500 years ago. The trail is short but steep, taking roughly 30–45 minutes from the parking area to the rim.

At the top, the 360-degree panoramic view was spectacular: the crater’s barren, moonlike interior, the expansive lava fields, the sparkling waters of Mývatn, and distant mountains stretching to the horizon. The rugged, lunar-like terrain at the crater’s edge made us feel as if we were exploring another planet, offering a stark yet fascinating contrast to the greenery and life around the lake below.