Kofun

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 () 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 . 

Related pages
William Gowland, English engineer made the first survey for Saki kofun group
Ernest Satow, English diplomat wrote about kofun in Kozuke for the Asiatic Society of Japan
Mozu Tombs

References
飛鳥高松塚 (Takamatsuzuka, Asuka), 橿原考古学研究所編, 明日香村, 1972.
前方後円墳 (Keyhole-shaped kofun), 上田宏範,  学生社, 東京, 1969.
前方後円墳と古代日朝関係 (Keyhole-shaped kofun and diplomatic relations between ancient Japan and Korea), 朝鮮学会編, 東京, 同成社, 2002.

Other websites

 Japanese Archaeology: Kofun Culture
 Kofun Period
 Prehistoric Archaeology of Japan  

Category:History of Japan
Category:Burial monuments and structures
Category:Kofun