The Mozu Tombs (�S�㒹�Õ��Q, Mozu Kofungun) are a cluster of several dozen ancient tombs in the Mozu area of Sakai City, immediately south of Osaka City. The cluster, along with some other tombs in the region, makes up the "Mozu-Furuichi Kofungun Ancient Tumulus Structures", which were designated a Cultural World Heritage Site in 2019.

The tombs were built in the 4th to 6th centuries for the ruling elite, with the larger, more elaborately shaped mounds signifying higher status than smaller ones and those of simpler shapes. The largest of the tombs is the Emperor Nintoku Kofun which is believed to be the tomb of ancient Emperor Nintoku. With the surrounding moats included, the tomb is about 800 meters long and 600 meters wide, making it not only Japan's largest grave, but also one of the world's largest. Less than a kilometer away lies the Emperor Richu Kofun, the third largest tomb in Japan.

Kofun tombs are large mounds of earth. Originally kept relatively free of vegetation, today most of them are covered by trees. Many of the larger tombs, including the ones of Emperor Nintoku and Emperor Richu, are of a keyhole shape and surrounded by moats. The tombs are generally not open to the public, and the larger ones are difficult to fully appreciate unless viewed from a high vantage point. The free observation deck on the 21st floor of the Sakai City Hall allows for such views from about a kilometer away.

A large number of medium and small sized kofun tombs are spread across the spacious and pleasant Daisen Park which stretches between the kofun of Emperor Nintoku and Emperor Richu. The park also offers a few attractions that are not directly related to the tombs:

Sakai City Museum

Hours: 9:30 to 17:15 (entry until 16:30)
Closed: No closing days
Admission: 200 yen
Typical visit duration: 45 minutes
English: Moderate

The Sakai City Museum documents the history of the port town of Sakai through the ages, beginning with a detailed account of aspects of the kofun tombs including artifacts excavated from inside the burial sites.

Japanese Garden

Hours: 9:00 to 17:00 (9:30 to 16:30 from November to March)
Closed: Mondays (or next day if Mon is a public holiday), New Year holidays
Admission: 200 yen
Typical visit duration: 30-40 minutes

Visitors can enjoy strolling around this scenic traditional Japanese garden. In addition to various water features and a picturesque bridge, there is also a rest house and multiple seating areas to take in the views.

Bicycle Museum

Hours: 10:00 to 16:30 (entry until 16:00)
Closed: Mondays (or next day if Mon is a public holiday), New Year holidays
Admission: 200 yen
Typical visit duration: 45 minutes
English: Moderate

This well-done museum documents the evolution of bicycles with various historical models on show to an exhibition of present technology. Sakai has long been a center of bicycle component manufacturing and hosts the headquarters of the global industry leader Shimano.