
Kofun (古墳) are earthen tombs or tumuli in Japan. They were constructed between the early 3rd century and early 7th century.
These burial mounds give their name to the Kofun period (middle 3rd century - early-middle 6th century).
Many of the kofun have a keyhole-shaped mound (zenpo-koenfun (前方後円墳)) which is unique to ancient Japan.
There are many types of Kofun including Zenpō-kōen-fun and Zenpō-kōhō-fun and Round Kofun and Square Kofun, and Octagonal Kofun and Joenkahofun and scallop-shaped kofun.