Everything about the Blarney Castle and Gardens was phenomenal. The state of the caste was awe inspiring, simply gorgeous. The grounds themselves are quite large and I didn't get the opportunity to see everything because I waited in line for over an hour to kiss the Blarney Stone but c'mon, you have to do it if you're there!
As mentioned, the grounds were stunning with lots of flowers, trees, and green space, they really were stunning. The view from the top of the castle was also quite phenomenal as well.
I was on a tour that brought me here so I'm unfamiliar with the entry cost but I'd say it's worth it. Just save enough time to explore everything!