Ruins of the Former Sagami River Bridge (旧相模川橋脚)

After the 1923 Great Kanto Earthquake and its aftershock in January 1924, wooden pillars emerged in the rice fields of the Shimomachiya District in Chigasaki, Kanagawa Prefecture, along the east bank of the Koide River.  This phenomenon is attributed to soil liquefaction, which caused the pillars to float upwards.

Monument with Numata's poem

Historian Yorisuke Numata (1867-1934) determined that these pillars were once bridge piers of a structure built in 1198 over the former course of the Sagami River by Inage Shigenari, who constructed it in memory of his wife.  In 1926, the site was designated a National Historic Site of Japan.  Further excavations in 2001 uncovered remnants of earth retainers located north of the piers, which were subsequently added to the National Historic Site designation.  In 2012, the site also received recognition as a Natural Monument.

A stone monument, inscribed with a poem written by Numata in classical Chinese, was erected at the site in 1970 to honor its history.

To preserve the wooden pillars, they are now stored inside concrete cylinders placed underground, while replicas are displayed above ground.

The site is also known for its cherry blossoms during spring.