Jennifer P.
Yelp
I'm not a Game of Thrones fan, but The Dark Hedges was on my list of cool nature-y sites to see while visiting Northern Ireland/UK!
We parked at the Hedges Hotel and walked over. It actually worked out well: there is an amazing fairy village right near the parking lot. It was so cool! We walked to the nearby Grace Village House, and then crossed the road to see the hedges.
The rows of beech trees (hedges), of which 150+ were planted in the 18th century, are intertwined and make for beautiful, unique scenery. Unfortunately many have been lost over the years (some due to increased tourism/buses driving through), but nonetheless, it's still such an impressive scene.
Due to it's sheer popularity, though, (and close proximity to Giant's Causeway and the Carrick-a-Rede rope bridge), it is a heavily visited site. If your aim is great pictures, I'd suggest going at off-peak times: perhaps in the morning or afternoon during the weekday. We were there around 4:30pm on a Wednesday, and there were several cars parked already, and tour buses pulling in around 5pm as we left.
The Dark Hedges are definitely a beautiful site to behold, GoT fan or not!