There is a photograph taken from the Hirakawa Bridge in the early Meiji period. On the right side of the photo, we can see the first gate of the Hitotsubashi-mon Gate, and on the left side, a guard station appears. What does this area look like today?
 Now, a large building stands directly ahead, and next to it runs a wide road that extends from the present-day Hitotsubashi. There is no trace of the gate or the guard station. Therefore, it is difficult to recognize that this area was once a part of Edo Castle.

 So, are there absolutely no remains of the gate?
 There are, in fact, faint remains. Right next to the current Hitotsubashi, there is a small stone wall reinforced with concrete. This is a remnant of the Hitotsubashi-mon Gate.

 To better examine these subtle stone remains, let's view them from the bridge. Then, it becomes clear that they are not isolated but part of stone walls from the Edo period that run along the current Nihon-bashi River. Thus, they can be considered part of the remaining stone walls along the river. While they may have been connected to the gate, it is unclear exactly which part of the gate they belonged to.

 Of course, the wooden bridge from the Edo period no longer exists, but today, a wide and sturdy reinforced concrete bridge for vehicles spans the area.
 Although the location is slightly shifted, Hitotsubashi still exists close to the original wooden bridge. Upon closer inspection, we will find that the current bridge was completed in November of Taisho 14 (1925).

 Inside the Hitotsubashi-mon Gate was the residence of the Hitotsubashi family (Hitotsubashi-Tokugawa family). The Hitotsubashi family, one of the Three Branches of the Tokugawa Family, was established in 1741 when Munetada (1721–1764), the fourth son of the eighth shogun Yoshimune (1684–1751), was granted a residence inside this gate. The residence occupied a large area between Hitotsubashi bridge and the neighboring Kandabashi bridge. Today, near the remains of the gate's stone walls and the current Hitotsubashi, there is a monument that commemorates the site.