Where Edo Castle’s Main Tower Once Stood: Honmaru Area Guide

📜 Detailed Historic Site Data

👀 Highlights

• Edo Castle’s Only Surviving Tamon: Of the tamon structures that once stood in the Honmaru, only Fujimi-tamon survives. Its longhouse-like exterior lets you imagine its dual role in defense and weapons storage.
• Longhouse Structure on Stone Walls: Looking up from the Hasuikebori Moat side reveals clearly how the tamon functioned as a defensive facility built atop the stone walls.
• Interior Viewing: Visitors can currently view the interior. Seeing the longhouse-like space and narrow windows up close makes its role as a defensive position and weapons storehouse easier to understand.

📌 Trivia

• The Role of a Tamon: A tamon was a longhouse-style building constructed on stone walls or earthen embankments. It served as both a defensive position and a storehouse for weapons and other equipment.
• Origin of the Name “Tamon”: The term tamon refers to a longhouse-style structure built on stone walls or embankments. It is sometimes said to derive from Tamonten, one of the Four Heavenly Kings, or from a defensive lookout function known as monomi.

Open the map to see the relationship between the Matsu-no-Oroka Corridor Site and Fujimi-tamon Defense House.

📜 Detailed Historic Site Data

👀 Highlights

• Visible Burn Marks: The burn marks on the Izu-stone exterior walls are evidence of the repeated fires of the Edo period. The discoloration of the stone hints at the intense heat of those fires.
• Precise Stonework: The cut-stone construction, with Izu stone stacked tightly and precisely, reflects advanced masonry techniques of the time. Notice how accurately the vertical and horizontal joints align.
• Contrast with Hasuikebori Moat: The scenery around the Stone Chamber and the moat changes with the seasons and adds to the quiet appeal of the site.

📌 Trivia

• Properties of Izu Stone: Andesite from the Izu Peninsula was transported to Edo by ship. Because of its fire resistance, it was widely used for stone walls and stone storehouses. Many stones used in Edo Castle came from Izu and Soshu, today’s Kanagawa area.
• Near the Ooku: The Stone Chamber stands near the area where the Ooku women’s quarters are thought to have been located during the Edo period. For that reason, it may have been used to protect valuable items during emergencies such as fires.

Open the map to see the relationship between Fujimi-tamon Defense House and the Stone Chamber.

📜 Detailed Historic Site Data

👀 Highlights

• Walk with Signs and Historical Materials: Although the area is now an expansive lawn, walking while imagining the Honmaru Palace buildings that once stood here helps convey the scale of the Honmaru.
• Experience the Scale: The openness of the great lawn is itself one of the site’s main attractions. It gives visitors a sense of the vast space that once served as the core of the Tokugawa shogunate.
• Connection with the Tenshudai and Fujimi-tamon: Viewing the Tenshudai Keep Base and Fujimi-tamon from the Honmaru Site helps you understand the castle’s structure around the Honmaru Palace in three dimensions.

📌 Trivia

• History of Fires: The Honmaru Palace burned down and was rebuilt repeatedly, beginning with the Great Fire of Meireki in 1657. Its final destruction came in 1863, during the turbulent final years of the shogunate, and it was never rebuilt afterward.
• The Core of the Tokugawa Government: The Honmaru Palace contained the Omote Palace, Nakaoku, and Ooku, supporting government affairs, ceremonies, and the shogun’s daily life.
• The Peak Under the Third Shogun Iemitsu: Edo Castle reached its greatest scale during the era of the third shogun, Tokugawa Iemitsu, when the Tenshudai was completed and the Honmaru Palace was fully developed.

Open the map to see the relationship between the Stone Chamber and the Honmaru Site.

📜 Detailed Historic Site Data

👀 Highlights

• Finely Detailed 1/30-Scale Model: The white walls, black roof tiles, and layered structure of the keep are carefully reproduced, giving visitors a concrete image of Edo Castle before the keep was lost.
• Best Viewed Together with the Tenshudai: Climbing the Tenshudai Keep Base before viewing the model, or doing the reverse, helps you understand the relationship between the actual stone base and the building that once stood on it.
• Use the Rest House: The nearby rest area is useful for a break, hydration, and browsing materials.

📌 Trivia

• Three Generations of Main Keeps: Edo Castle’s keep was rebuilt three times: in the Keicho period (1607), Genna period (1623), and Kan’ei period (1638). The Kan’ei-period keep was the largest, with five above-ground stories, one basement level, and an estimated height of about 58 meters.
• Hoshina Masayuki’s Famous Advice: The decision to abandon reconstruction after the fire is traditionally linked to Hoshina Masayuki, younger brother of Tokugawa Iemitsu and adviser to the fourth shogun, Ietsuna, who argued that the keep was merely a symbol of military power and that the suffering of the people should be prioritized.

Open the map to see the relationship between the Honmaru Site and the reconstructed main-keep model.

📜 Detailed Historic Site Data

👀 Highlights

• View from the Lookout: One of the best viewpoints in the Honmaru Area, overlooking the Ninomaru Garden, Swan Moat, and the direction of Kitanomaru. From the height of the stone walls, you can sense the scale of the castle.
• Contrast Between Modern Tokyo and History: The view of the Ninomaru Garden with central Tokyo’s high-rise buildings behind it creates a striking composition where the Edo period and the present overlap.
• Cherry Blossoms in Spring: During cherry-blossom season, the contrast between the flowers and the stone walls is especially beautiful.

📌 Trivia

• Connection to the Kitchen: As the name “Daidokoro-mae,” meaning “in front of the kitchen,” suggests, the turret once stood near the kitchen area of the former Honmaru Palace. It helped protect one of the everyday working areas of the shogunate.

Open the map to see the relationship between the reconstructed main-keep model and the Daidokoro-mae Sanju-yagura Turret Site.

📜 Detailed Historic Site Data

👀 Highlights

• Climbing Experience: Climbing to the top of the Tenshudai is one of the most recommended experiences in the Honmaru Area. The view from the top is among the most open and expansive in the East Gardens.
• Stone Marks on the Base: The stones of the Tenshudai bear marks carved by daimyo families as proof of the stones they transported for construction. Searching for them as you walk adds another layer of enjoyment.
• Scale of the Stone Base: Seeing the stone base up close—about 11 meters high and 41 meters wide—reveals the massive foundation needed to support the Kan’ei-period keep, which stood about 58 meters tall.
• Connection with the Reconstructed Keep Model: After climbing the Tenshudai, viewing the 1/30-scale model in the rest house makes it easier to imagine the keep that once stood on this base.

📌 Trivia

• Hoshina Masayuki’s Counsel: Hoshina Masayuki, younger half-brother of Tokugawa Iemitsu and lord of the Aizu Domain, is said to have argued against rebuilding the keep, saying that it was merely a symbol of military power and that the suffering of the people should be considered. His counsel shifted the shogunate’s policy, and the keep was never rebuilt.
• Types of Stone Marks: Stars, circles, written characters, and family crests can be found carved into stones, differing by the daimyo family responsible for them.

Open the map to see the relationship between the Daidokoro-mae Sanju-yagura Turret Site and the Tenshudai Keep Base.

📜 Detailed Historic Site Data

👀 Highlights

• Traces of the Drawbridge: The metal fittings on the gate pillars are said to have held pulleys for the drawbridge. They are subtle details, but they bring the gate’s defensive function to life.
• View Toward the Tenshudai: Entering through the gate, the Tenshudai Keep Base appears directly ahead. This helps visitors understand the gate’s role in the northern defense of the Honmaru.
• Hirakawa Moat and Inui Moat: The surrounding moat scenery is beautiful and gives a strong impression of the northern edge of Edo Castle.

📌 Trivia

• The Meaning of “Hanebashi”: Hanebashi means a bridge that can be raised. By lifting the bridge in an emergency, the gate could block access and strengthen the defense of the Honmaru.
• A Useful Exit Today: Today the gate is used as an entrance and exit of the Imperial Palace East Gardens and is convenient for visitors heading toward Takebashi Station.

Open the map to see the relationship between the Tenshudai Keep Base and Kitahanebashi-mon Gate.