Introducing the highlights (8 geosites) of the East Izu area

The highlights of the East Izu area
Omuroyama Volcano
Mt.Omuro is the largest scoria cone in the Izu peninsula. A volcano with a crater about 300m in diameter, created by eruptions about 4000 years ago, with lava splashes and volcanic bombs falling around the crater.
Yamayaki (Burning of the hill) is held every year to maintain the beautiful mountain shape. The mountain is designated as a national monument and climbing on foot is prohibited. Please use a lift.
Jogasaki Coast
About 4,000 years ago, lava flowing from Mt. Omuro reclaimed a part of the sea and created new land. Walking around the promenade from Boranaya to Kadowakizaki, you can enjoy the dynamic terrain created by lava.
From the suspension bridge connecting the sea cave between Hanshiro otoshi-cliff and Kadowakizaki cape, you can observe "columnar joints" formed when lava cools and shrinks near the sea surface such as Tsubakuro Island.      
This is a part of Jogasaki coastline created by lava flow out from Mt. Omuro about 4,000 years ago. The lava flow spread flat and the surface of the lava is jagged. When the lava flow reached here, the surface that has cooled and solidified first were cracked resulting jagged surface (“igaiga”). From the table-like rock with little undulation, you can overlook Jogasaki-beach widely.
There is a circular hole called Pothole on Kannonhama Beach east of Igaigane. In the hole, a spherical rock with a diameter of 70 cm rolls by the breaking waves. Pot hole isn’t rare but large and round stone is rarely left in the hole. It’s designated as a natural treasure of Ito city.       
Ippekiko Lake
Lake Ippekiko and Numaike-pond are craters of volcanic maar that erupted explosively about 100,000 years ago. A large amount of fine volcanic ash accumulated in the crater, so this hollow had an environment where water was difficult to drain, and it became a swamp. About 4000 years ago, long after the formation of Lake Ippekiko, lava flowing from Mt. Omuro ran into the lake, creating the twelve small islands.
Siranuta pond
Shiranutanoike, it’s a mysterious pond surrounded by a primeval forest. Amagi volcanoes erupted until about 200,000years ago. After that, the mountains were eroded by rains, strong winds and frequent earthquakes. It is believed that the landslides that occurred during the erosion process created a depression, and that water accumulated to create a pond.
In early summer season we can see an unusual chunk of forest green tree frog’s egg in the brunch of a tree.
More (3 left)
Atami Urban area
Atami is a city built on rugged terrain where the eastern half of the Taga volcano was eroded by strong waves of Sagami Nada.
It has long been counted as one of Japan's three major hot springs and has a long history as a spa. With the opening of the Tanna Tunnel in 1934, it has become a major tourist city.
Sakura Park
Sakura no Sato is a park at the northwestern foot of Mt. Omuro created by an eruption about 4000 years ago. The beautiful shape of Mt. Omuro is clearly visible from the park. Scoria raft and lava cave can be observed in the park.
In addition, various kinds of cherry trees continue to bloom from September to May of the following year.
Hatsushima Island
Hatsushima is a small resort island floating in the Sagami Nada, about 10km southeast of Atami. This flat terrain is a land that has been cut by waves and rises to the surface. If you look closely, you can see that there are several levels of flat surface, and the island has been formed by the uplift that has been repeated in the past.