There used to be the Ote Gate around here. It was the official gate to enter the castle compound and the outer moat surrounded this area. Townspeople were not allowed to use this gate. They had to use the East Gate, a side gate, if necessary.
This area used to be the third enclosure and it was high-ranking samurais residential area.
This is the current main entrance to the castle. As you see, there is a moat on your right. The moat originally surrounded the area, so you had to turn right here and go to the Drum Gate along the moat.
This is the Drum Gate, the entrance to the second enclosure. It was restored in 1999. A drum had been set inside of the tower of the gate. The drum would be beaten if a fire would occur. It was also beaten when all samurais were ordered to come to the castle
This gate is called the Black Gate. It is not because it is black. Black was the most honorable color in those days. The gate was the most important one as the entrance to the main enclosure. So, it was named the black gate to show its honorability.