There is an obscure cave on the other side of the hill.

A. admired

B. notorious

C. infamous

D. well-known

Answer: Option D

Solution(By Examveda Team)

Obscure : not discovered or known about; uncertain.
Admired : regard with respect or warm approval.
Notorious : famous or well known, typically for some bad quality or deed.
Infamous : well known for some bad quality or deed.
Well-known : widely or generally known.

Antonym of Obscure is Well-known