Walking path in the city

From here, the square continues across Nijubashi Bridge to Wadakura Fountain Park. This is the area known as the Imperial Palace Square. This was once the residence of many feudal lords, but is now open to the public as a national park under the jurisdiction of the Ministry of the Environment. Crossing Uchibori-dori Street leads to a shady grassy square. In the past, this area was bustling with office workers from the surrounding buildings gathering at lunchtime to eat and play volleyball. Before we knew it, office workers came to be called businessmen, and these days you no longer see them. There are also many tourists, citizen runners, cyclists, and people quietly enjoying their portable music players on benches. Recently, there are also many foreigners, giving the area a very international feel.

There is a beautiful moat in the outer gardens of the Imperial Palace. For a long time, clean water flowed into the moat from the Tamagawa Aqueduct, one of the drinking water sources of Edo. However, due to changes in the urban structure after the Meiji period, the Tamagawa Aqueduct was replaced by a modern water supply, and in 1965, the Yodobashi Water Purification Plant was abolished and surplus water no longer flowed into the moat, making it a closed water area. Although measures were taken to improve the deterioration of water quality after that, a full-scale water quality improvement plan was formulated in 2010 as a comprehensive measure, which included strengthening the purification equipment of the Ministry of the Environment, changing the sewerage route of the Tokyo Metropolitan Government, and cooperating with surrounding private landowners. The first private project is the "Otemachi 1-1 Plan (Tentative name)," a plan to rebuild the Resona Maruha Building and the Mitsubishi Tokyo UFJ Bank Otemachi Building. This project utilizes the city planning special exemption system based on the Urban Renewal Special Measures Act and is subject to volumetric relaxation. As a contribution to the local community, a storage tank and purification equipment will be installed to improve the water quality of the moat, and water will be replenished and purified during droughts.

To install the intake and discharge points, the stone walls of the moat were partially dismantled and then rebuilt. There are many stone walls in the Imperial Palace, which were built at the expense of the feudal lords of various domains. A huge number of stones were carefully stacked one by one. The strength was ensured by the interlocking of stones of different sizes. Even though there was advanced technology at the time, it is likely that there was repeated trial and error on site. Today, the structure is determined by calculations based on standards, and construction is carried out according to blueprints. It is thanks to the accumulated experience of our predecessors that we are able to build large-scale and complex structures in a short period of time, which is incomparable to what was possible back then. However, I thought that it might be meaningful for us, who use today's technology as if it were a given, to know and learn from the wisdom of our predecessors from time to time.

Let's continue walking. Leaving the moat behind, we pass Gyoko-dori Street, a restored four-row avenue of ginkgo trees from the Imperial Capital Reconstruction Project after the Great Kanto Earthquake, and enter the Marunouchi business district. Beyond the perspective view, the brick Tokyo Station building appears as it did when it was built 100 years ago. There are many historical buildings nearby, such as the Japan Industrial Club Building built in the Taisho era, the Meiji Life Insurance Building built in the early Showa era, and the restored Mitsubishi Ichigokan building from the Meiji era. There are many stylish cafes on Marunouchi Nakadori Street. If you get tired, it might be a good idea to take a break there. It's a walking path where you can feel and learn a little about history.