Dartmouth…?

Downright heading towards the gothic, heroine left the original for future development (7)

CLUE

Downright heading towards the gothic, heroine left the original for future development (7)

_ E _ _ _ _ _

No, not it.

Downright heading towards the gothic, heroine left the original for future development (7)

_ E _ I _ _ _

One of the clues is pointing on a compass.

It was a capital I.

And twyngwyn has it.

Downright heading towards the gothic, heroine left the original for future development (7)

WORDPLAY

downright heading towards -> SE

the gothic heroine -> Mina

left -> L

SE+Mina+L

WHOLE DEFINITION

original for future development = seminal

Over to you, twyngwyn.