tomb, mound
墳 centers on an earthen burial structure: a tomb or mound raised over a grave.
墳 combines 土 (earth) with 賁, which likely contributes the sound and may have originally suggested something large or raised, fitting a burial mound.
The left side is earth 土, and the right side 賁 looks like a rich, decorated mound. Picture a grand earthen tomb raised from the ground.
For フン, imagine a funeral mound: fun -> フン, and the earth 土 is piled high over the tomb.
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ancient burial mound; barrow; tumulus
grave; tomb
keyhole-shaped ancient Japanese tumulus
tumulus; grave mound
burial mound with square flat base and round top
octagonal burial mound (Kofun period)
round burial mound
Kofun people; people of the Kofun period
Kofun period (of Japanese history, 250-538 CE); Tumulus period
burial mound; tumulus
tomb embedded in a Yayoi period barrow
grave; tomb; graveyard
desecration of a tomb; grave excavation
(crime of) grave excavation
flat-topped burial mound