古墳

1. Origins, structure, and basic meaning

• Structure: It is read こふん. 古 contributes antiquity and 墳 a tomb or burial mound, forming a word for an ancient tomb, especially a substantial earthen burial mound.
• Basic usage: It is used for ancient burial sites considered as archaeological remains. In the example, a mound discovered on a hill provides clues to local history.
  • 丘の上で見つかった古墳は、地域の歴史を知る手がかりになった。

2. Common pitfalls and similar expressions

• A general grave versus an ancient burial site
  • 墓 broadly names graves regardless of age or size, while 古墳 treats an ancient tomb as a historical or archaeological site.