Udozuka Kofun

Udozuka Kofun is a Kofun period burial mound in the Kasugaoka neighborhood of the town of Heguri, Nara, in Japan's Kansai region. It stands at the tip of a branching ridge at the eastern foot of the Ikoma Mountains, which run along the border between Osaka Prefecture and Nara Prefecture. The tumulus was designated a National Historic Site of Japan in 1971.

The mound is a zenpō-kōen-fun, the keyhole-shaped form with one square end and one circular end when seen from above. It is 60.5 meters long, with a circular rear portion about 35 meters across and 9 meters high and a rectangular front portion 31 meters wide. It was built in one tier, and a moat approximately 2 meters wide surrounded it. A row of cylindrical haniwa stood along the mound, although no trace of fukiishi roofing stones has been found.

A horizontal-entry stone burial chamber opens to the south of the rear circular mound. It is about 6 meters long, 2.1 meters wide, and 4.4 meters high, with an entrance passage about 8.2 meters long and 2.1 meters wide containing a culvert-type drainage ditch. A house-shaped tuff sarcophagus stood in the chamber, and the bottom of another tuff sarcophagus lay in the passage.

Excavations in 1969 recovered a four-animal bronze mirror, a large iron sword, gilt bronze horse equipment, jewels, and Sue ware pottry. The mound was probably built around the mid-6th century in the late Kofun period and is regarded as a rare megalithic tomb with clearly excavated artifacts. Kofun are the great burial mounds of ancient Japan, built mainly between the middle of the third century and the early seventh century CE.

The Udozuka Kofun is located at the tip of a branching ridge at the eastern foot of the Ikoma Mountains, which run north and south along the border between Osaka Prefecture and Nara Prefecture. Archaeological excavations were carried out in 1969 . It is a zenpō-kōen-fun (前方後円墳), which is shaped like a keyhole, having one square end and one circular end, when viewed from above, with a total length of 60.5 meters, making it the largest tumulus in the Heguri region. The posterior circular portion has a diameter of about 35 meters and height of about 9 meters, and the width of the anterior rectangular portion is 31 meters. The mound was constructed in one tier, although no trace of fukiishi roofing stones have been found, the mound had a row of cylindrical haniwa. A moat (approximately 2 meters wide) has been found around the mound.

The horizontal-entry stone burial chamber opens to the south of the rear circular mound was built with huge stones. The burial chamber is about 6 meters long, 2.1 meters wide, and 4.4 meters high. The entrance passage is about 8.2 meters long and 2.1 meters wide, with a culvert-type drainage ditch in the center. A house-shaped stone sarcophagus made of tuff is located in the burial chamber, and the bottom of another tuff sarcophagus is located in the entrance passage. Excavated grave goods include a four-animal bronze mirror, a large iron sword, gilt bronze horse equipment, jewels, and Sue ware pottry. It is believed to have been built around the mid-6th century in the late Kofun period, and is considered a rare example of a megalithic tomb with clearly excavated artifacts.

The tumulus is about a five-minute walk from Tatsutagawa Station on the Kintetsu Railway Ikoma Line.