Guide
The Ooka River is a second-class river flowing through Yokohama City, Kanagawa Prefecture, eventually emptying into Yokohama Port. In its upper reaches, the area is affectionately known as the "Sasagegawa" area. This river holds a deep history, once featuring an inlet known as Maita Bay, and today it serves as a vital waterfront space within the urban landscape. The well-maintained promenade along the riverbanks offers a peaceful escape from the city's hustle and bustle, allowing visitors to enjoy tranquil waterside views.
The history of the Ooka River is profound. Historically, a large inlet called Maita Bay existed in this vicinity. During the Sengoku (Warring States) period, the Kira clan, based at Maita Castle, controlled this area, and the river played a significant role in maritime transport. Records also suggest that during the Muromachi period, this waterway was used to transport timber for the reconstruction of Tsurugaoka Hachimangu Shrine. The presence of traditional timber wholesalers (Zaimoku-donya) around the river today serves as a living testament to its history of water transport. From the mid-17th century, land reclamation processes transformed the area into its current topography.
The Ooka River area is known for unexpected encounters with nature. For instance, in October 2024, a phenomenon where the water surface glowed due to the proliferation of bioluminescent plankton (noctiluca scintillans) was observed. The river has also been a center of public interest for wildlife, such as the famous appearance of the wild bearded seal "Tama-chan" in 2002. It is a place where urban life meets natural wonders. Additionally, various bridges spanning the river—such as Aoki Bridge, Kubo Bridge, and Okubo Bridge—offer diverse vantage points to view the water from different angles.
The Ooka River presents a different face depending on the season and time of day. During bright daylight hours, the area is ideal for a pleasant stroll along the paved paths, allowing you to observe the movement of the water and the surrounding cityscape. At night, the scenery shifts as city lights reflect off the water's surface, and under certain conditions, you may witness the magical glow of bioluminescent organisms. Depending on the season, you can also enjoy the changing colors of the local vegetation and the shifting river environment.
Visitors can easily connect with the water through various activities. The primary activities include walking along the well-maintained promenade and enjoying the views from the many bridges. Given the area's historical background, it is a wonderful place to reflect on the history of water transport while observing the architecture of the old timber wholesalers. It functions effectively as a space for urban nature observation.
The area around the Ooka River encompasses various facets of Yokohama's urban function. The landscape transitions from the Sasage district in the upper reaches to the Sakuragicho and Minato Mirai areas in the middle reaches, and finally toward the Negishi area downstream. The Sakuragicho and Minato Mirai districts, in particular, offer a striking blend of modern architecture and river scenery. The many bridges in the area provide unique perspectives of the changing landscape.
As the Ooka River Promenade is an open, public outdoor space, no special preparation is required, though comfortable walking shoes are highly recommended for your stroll.