The Parnell Rose Gardens is a section of land given over to roses. It's not a formal attraction with an entry fee. Just walk into the gardens, which aren't walled off. Remember that roses bloom during the summer, so you might skip this if it isn't between October and April.
In the private garden, roses are vying for beauty, and you can't feel that it is in the severe winter!
This is a free park with a constant stream of tourists. You can smell the fragrance of roses in the Parnell Rose Garden, where there are many kinds of roses to enjoy.