The Castle Gate is located to the south of the castle near at the junction of Old Road / Beech Avenue and Castle Avenue.
The gate comprises of a strong stone structure and only one remains but at one time there would have been two identical turret style structures. The gate itself was made of cast iron and was relocated to what is known as the white gate.
The date the structure was built is unknown along with when it was decommissioned, however the new castle avenue was built sometime after the 1920s, so you could say any time after the early to mid 20th century it was no longer used and the other stone structure demolished.
I have recreated what the gate would have looked like when in use