The most common and most likely answer to this crossword clue is the 10 letter word UNTRAMPLED
I've seen this crossword clue in The Guardian
U
N
T
R
A
M
P
L
E
D
Buddy explains!
The straight part
We know that "Like virgin territory" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case like virgin territory = untrampled.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.