Travel about 60 miles (100 kilometers) out of Tokyo and into Kanagawa Prefecture and you’ll find yourself in the Great Boiling Valley of Owaku-dani. The live volcanic valley makes for one of the most enjoyable -- and smelliest -- day trips from the big city. The area has long appealed to domestic and foreign tourists for its beautiful scenery, hot springs, occasional scenic views of Mount Fiji and for black eggs, eggs that are hard boiled in the sulfurous waters, turning their shells black.
A short walking trail leads from the base of the Hakone Ropeway past bubbling sulfurous pools to a tourist stand where you can purchase black eggs. Local legend claims that eating a single egg will extend your life by seven years. From the Owaku-dani tourist station, you can either return on the Hakone Ropeway or continue to hike up to the peak of Mount Kamiyama and nearby Mount Komagatake. From there, a ropeway will ferry you down to beautiful Lake Ashi.