The most common and most likely answer to this crossword clue is the 3 letter word TOR
T
O
R
More clues leading to the result TOR
Buddy explains!

The straight part
We know that "Prominent feature" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case prominent feature = tor.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TOR mean?
TOR noun- A craggy outcrop of rock on the summit of a hill, created by the erosion and weathering of rock.
- (South-West England) A hill with such rock formation.
- A tower; a turret.
- Hard, difficult; wearisome, tedious.
- Strong, sturdy; great, massive.
- Full; rich.