Ireland Dungeons & Dragons: Honor Among Thieves Sweepstakes

https://www.ireland.com/en-us/features/us/dungeons-and-dragons-competition/
answer is The Giant’s Causeway
The prize includes:

2 roundtrip standard economy airline tickets from any USA Aer Lingus gateway to Dublin, Ireland compliments of Aer Lingus
2 return transfers from Dublin Airport to Belfast
4 night’s accommodation in Belfast with breakfast each morning