Ōwakudani (大涌谷 lit. "Great Boiling Valley"?) is a volcanic valley with active sulphur vents and hot springs in Hakone, Kanagawa Prefecture, Japan. It is a popular tourist site for its scenic views, volcanic activity, and especially, Kuro-tamago (黒卵 lit. "black egg") — a local specialty of eggs hard-boiled in the hot springs. The boiled eggs turn black and smell slightly sulphuric; consuming the eggs is said to increase longevity. Eating one is said to add seven years to your life. https://en.wikipedia.org/wiki/%C5%8Cwakudani Hakone is the location of a noted Shinto shrine, the Hakone Gongen, which is mentioned in Heian period literature. During the Gempei War, Minamoto no Yoritomo prayed at this shrine for victory over his enemies, after his defeat at the Battle of Ishibashiyama, which was fought in neighboring Manazuru. As with the rest of Sagami Province, the area came under the control of the late Hōjō clan of Odawara during the Sengoku period. After the start of the Edo period, Hakone-juku was a post station on the Tōkaidō highway connecting Edo with Kyoto. It was also the site of a major barrier and official checkpoint on the route known as the Hakone Checkpoint (箱根関所 Hakone sekisho?), which formed the border of the Kantō region. Under the Tokugawa shogunate, all travellers entering and leaving Edo along the Tōkaidō were stopped here by officials. Their travel permits and baggage were examined to enforce Tokugawa laws that restricted the travel of women and weapons. After the start of the Meiji Restoration, Hakone became a part of the short-lived Ashigara Prefecture before becoming part of Ashigarashimo District in Kanagawa prefecture in August 1876. Hakone attained town status in 1889. The imperial household established the summer Hakone Imperial Villa close to the lake. After merger with five neighboring towns and villages in September 1956, it reached its present boundaries. The economy of Hakone is strongly dominated by the tourist industry. Hakone is noted for its onsen hot spring resorts, which attract both Japanese and international visitors due to its proximity to the greater Tokyo metropolis and to Mount Fuji. Sights include the volcanically active Owakudani geysers and Hakone Shrine on the shore of the lake, as well as the Hakone Botanical Garden of Wetlands. In April the cherry blossoms (sakura) and in autumn the Miscanthus sinensis (susuki) are noted sights. ... https://www.youtube.com/watch?v=OFqr3bh8nUg