Matsushima Bay has more than 230 islands of various sizes,* and is surrounded by mountains around 100 meters high. The beautiful scenery of many islands floating in the sea surrounded by mountains leaves an impression on visitors.

Matsushima Bay’s islands are composed of tuff, which is made of volcanic ash, and siltstone and sandstone, which are made of sand from the ocean floor. These rocks originate in the Neogene period, a geological period that spans from the birth of the earth to the present, and were formed between 23 million and 2.6 million years ago.

The shape of the islands we see today is the result of changes in sea level. The last glacial period of the geological Quaternary period (present period), when the earth was very cold, was about 19,000 years ago. At that time, the sea level was about 100 meters lower than it is now, and Matsushima Bay had more land than it does now. However, with subsequent global warming, the ice melted and the sea level rose, and about 6,000 years ago it was almost as high as it is today. As the sea level rose, the land became ocean, and more than 230 islands were born.

In addition, the seawater gradually eroded the islands made of tuff, siltstone, and sandstone, creating cliffs called "sea cliffs" which can be seen on most of the islands in Matsushima Bay.

In Matsushima Bay, 75% of the islands are less than 10 meters above sea level. If the sea level had risen higher in the warming, many of the islands would have been submerged. The only major river flowing into the bay is the Takagi River. The fact that there was not much sediment flowing from the river to the sea was also a factor that prevented the bay from being completed filled in. The beautiful scenery we can see today is the result of a miraculous balance of nature.
*The number of islands is based on the Miyagi Prefectural Government's 1981 "Prefectural Natural Park, Matsushima, Scientific Report" and the Miyagi Prefectural Board of Education's 2010 "Conservation and Management Plan for Matsushima, a Special Place of Scenic Beauty.”

Pine forests are a defining part of Matsushima’s scenery that cannot be left out. Pine forests play an important role as an accent of green against the blues of the sea and sky and the white of the sea cliffs.

Pine trees are evergreen conifers that not only tolerate sea breezes and waves, but also prefer thin, dry soil with low nutrient content. There are two types of pine trees in Matsushima Bay: red pine and black pine. Red pines grow naturally on the islands and along the coast, black pines also grow naturally, but the locals have planted additional black pines to serve as “disaster prevention forests.”

These forests were originally planted to prevent sand from the beach flying into the villages and fields, and are now an integral part of the beautiful scenery of Matsushima. The planting of black pines is thought to have started around the Edo period, and the trees in each region were carefully protected. The trees were thought of as a valuable natural resource. In addition to providing defense against natural disasters, people have used fallen leaves as household fuel. The locals’ collection of fallen leaves allowed the land to maintain a low nutrient level, the ideal condition for pine forests. Many of disaster prevention forests were washed away by the tsunami of the Great East Japan Earthquake, but they are being replanted now. Matsushima’s beautiful scenery has been created not only by a miraculous balance of natural elements, but also the lives of the people who live there.