Grave
Tomb
noun
A tomb grave is a grave... or it could be a tomb. Or maybe both.
ふんぼ
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
ツタンカーメンの墳墓は絶対に訪れた方がいいよ。
You should definitely visit the tomb of Tutankhamen.