Nagoya Castle Stone Wall Repair Work
No, the moat isn't being filled in. Stones are lined up by "sections" for some repair work or reconstruction.
Early into the Edo period, as it became clear that a second showdown with the Toyotomi clan would likely happen, Tokugawa Ieyasu ordered that Nagoya Castle be built on the site of the old Oda Castle where Nobunaga was born. As the area stood at an important strategic point along the Tōkaidō Road, Ieyasu wanted to make sure that he had a strong fortress to control the approach midway between Osaka and Edo. Work on the castle started in 1609 and it was completed in 1612. Nagoya Castle became the seat of the Owari Tokugawa clan, who relocated here from nearby Kiyosu Castle, which was dismantled and parts of it were used in the building of Nagoya Castle. The castle with its Honmaru Palace, was along with Himeji Castle, considered one of the most beautiful ones in the entire country. Nagoya Castle was destroyed in a bombing raid by US forces in May 1945 during World War II. The castle was rebuilt, this time using Ferro-concrete and steel in 1959. The Honmaru Palace is also being rebuilt, using traditional materials and techniques when applicable. The first segment opened in October 2010, and the construction will finally wrap up in 2017.