Yagura-mon: The Tower Gate That Defined Japanese Castle Defense

Castle Gates Have a Hierarchy

Japanese castles feature various styles of gates. There are simple yakui-mon gates, korai-mon gates with roofs, and yagura-mon gates with turrets built on top.

Among these, the yagura-mon is considered the most prestigious. Positioned at strategic points such as the main entrance (ote-mon) or the gateway to the castle’s central compound (honmaru), it served both as a defensive stronghold and a symbol of the castle lord’s authority.

This article explores the structure and role of yagura-mon gates, along with castles where you can still see them today. May it inspire you to pay closer attention to castle gates on your next visit.

What Is a Yagura-mon?

A yagura-mon is a type of castle gate with a turret (yagura) built above the passageway. It is also called a “nikai-mon” (two-story gate).

With gate doors on the ground floor and a turret on the upper floor, this design differs from ordinary gates that function merely as passages. The yagura-mon also serves as a defensive structure, allowing soldiers to monitor the surroundings from above and attack enemies through small openings called sama using bows and firearms.

These gates were often placed at important locations such as the main entrance (ote-mon) or the entrances to the honmaru and ni-no-maru compounds. They are the “face of the castle”—often the first structure visitors encounter.

Structure of a Yagura-mon

A yagura-mon consists of two main parts: the lower section and the upper section.

Lower Section (Gate Doors)

The gate doors were made of heavy timber, built to withstand enemy attacks. Important gates sometimes had iron plates attached to the surface or decorative metal studs called chibyo.

Upper Section (Turret)

The turret above the gate resembles a corridor built on top of stone walls. Soldiers stationed inside could attack enemies through the sama openings. Some gates also featured ishi-otoshi—trapdoors in the floor that allowed defenders to drop stones or pour boiling water on enemies directly below.

Many yagura-mon gates were connected to stone walls and tamon-yagura (long barrack-style turrets), forming part of the castle’s overall defense line. The gate did not stand alone but worked in coordination with surrounding defensive structures to protect the castle.

Masugata-mon and Yagura-mon

Castle entrances often featured a structure called a masugata-mon—a square space (masugata) enclosed by walls or stone ramparts, with two gates positioned at different angles.

In a typical masugata-mon, a korai-mon stands at the outer entrance while a yagura-mon guards the inner entrance. Enemies who entered could not proceed straight ahead and would be trapped in the square space, exposed to attacks from three directions.

Kanazawa Castle’s Ishikawa-mon and the former Sakashita-mon of Edo Castle both employed this configuration.

Castles Where You Can See Yagura-mon Gates

Here are some castles where you can still see yagura-mon gates today.

Himeji Castle: Nu-no-mon Gate

The World Heritage Site of Himeji Castle retains several yagura-mon gates, and Nu-no-mon is particularly impressive. Standing approximately 10 meters tall, it is the largest yagura-mon in the castle and designated an Important Cultural Property of Japan.

Nu-no-mon’s distinctive feature is its two-story turret section—a rare double-layered yagura-mon (niju yagura-mon). Very few such gates survive nationwide, making it exceptionally valuable. It also has hidden ishi-otoshi openings, preserving the defensive concepts of the era.

Obi Castle: Ote-mon Gate

The Ote-mon Gate of Obi Castle in Nichinan City, Miyazaki Prefecture, was reconstructed in 1978. Dr. Michio Fujioka, a leading expert in castle architecture, supervised the design and reconstruction, which used 100-year-old Obi cedar. Traditional construction methods were employed, with no nails used in the assembly.

Standing 12.3 meters tall, this magnificent gate conveys the dignity befitting the entrance to a castle town.

Kanazawa Castle: Ishikawa-mon Gate

Kanazawa Castle’s Ishikawa-mon is a masugata-mon designated as an Important Cultural Property of Japan. Visitors pass through the outer ichi-no-mon (korai-mon), cross the masugata space, and then reach the inner ni-no-mon (yagura-mon).

With turrets surrounding three sides of the square, this gate complex boasts one of the strongest defensive layouts among all masugata-mon in Japan. Its white walls and lead roof tiles create a beautiful appearance, and the view from the Kenroku-en side is one of Kanazawa’s most iconic landscapes.

Edo Castle: Sakashita-mon Gate

The Sakashita-mon Gate at the Imperial Palace once served as the entrance to the Nishi-no-maru compound of Edo Castle. During the Edo period, it was a masugata-mon consisting of a korai-mon and a watari-yagura-mon (connecting turret gate). In 1887, the korai-mon was removed, and only the watari-yagura-mon remains in its current location.

This gate is also known as the site of the Sakashita-mongai Incident of 1862, when Chief Senior Councilor Ando Nobumasa was attacked by Mito domain ronin.

Pay Attention to Gates When Visiting Castles

When visiting castles, most people focus on the main tower (tenshu), but gates are equally important structures that convey the castle’s history and the technology of their time.

When you encounter a yagura-mon, take a moment to stop and look up. Notice the weight of the gate doors, how they connect to the stone walls, and the commanding presence of the turret above. These gates served to defend the castle, intimidate visitors, and welcome guests—all at once.