Iwase Senzuka Kofun Group

The Iwase Senzuka Kofun Group is a burial mound complex with over 900 individual structures scattered across eastern Wakayama near the Ryumon Mountains. The mounds vary in size and shape, each constructed with different burial chamber techniques that changed over the centuries.

These burial mounds were built between the middle of the 4th century and mid-7th century during the formation of early Japanese state systems. The site shows how burial practices and social organization evolved significantly across these three centuries.

The mounds in different shapes tell you how society was organized based on who people were. Circular, square, and the less common keyhole-shaped structures show you these social divisions when you walk among them.

The Kiifudoki-no-oka Museum of History displays objects from the site and explains ongoing archaeological work in the area. A visit to the museum before exploring the grounds helps you understand what you are seeing among the mounds.

The burial chambers reveal an unexpected evolution from simple clay-lined structures with wooden coffins to elaborate stone chambers made of chlorite schist with supporting beams. This technical advancement shows how the power and resources of the elite grew dramatically over these centuries.