The most common and most likely answer to this crossword clue is the 17 letter word WESTON-SUPER-MARE
I've seen this crossword clue in The Guardian
W
E
S
T
O
N
-
S
U
P
E
R
-
M
A
R
E
More clues leading to the result WESTON-SUPER-MARE
- Type of film mentioned wonderful horse somewhere on the south-west coast
- Watts set out riding magnificent horse in town
- Riding lovely horse following direction for seaside town
- Town street crossed by setters having great horse-riding experience?
- This could be 20’s warmest northern resort!
- Up in Somerset, we ran new resort town
- Ruined steamer owner’s getting high in seaside town
Buddy explains!

The straight part
We know that "Town" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case town = weston-super-mare.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.