2 Best Sights in Jeju-do, South Korea

Designated as a UNESCO World Heritage Site, this cave was created many millennia ago when the island's volcano was still active. Manjanggul is the largest lava cave on the island, stretching for about 4.5 miles, though less than a mile is open to the public. The path into the cave is well lit but it still feels dark and spooky. Manjanggul is part of the larger, 300,000-year-old Geomun Oreum lava tube system and is packed stalactites, stalagmites, and a lava column—it's a photographer's playground.

This grotto carved into the side of Sanbangsan mountain is a significant Buddhist shrine and one of the most important and popular cultural sites on the island of Jeju. The steep staircase climb is exhausting but well worth the effort for the panoramic ocean views. Once at the top, visitors can drink from the fresh mountain spring and make a donation to the life-sized Buddha statue.