Fern Hill is the name of the farm where Dylan Thomas spent his childhood summers in Wales. It also just so happens to be the setting of his poem.
Exciting, right? C'mon, imagine your parents walking in to your room and saying, "Guess what? You get to spend this summer alone in rural setting and run around outside by yourself near a barn! Who's in?" Shmoop just might cling to our iPads for dear life. But Dylan Thomas? That kid's totally game.
But there's more to it than just a place. Throughout the poem, Thomas praises the pastoral setting, the colors of nature, and the seemingly endless day. It's as if his description of Fern Hill embodies all the love and loss of his cherished youth—which could only have happened at an idyllic place like Fern Hill. So the title is a place name, sure, but it's also a time in the speaker's life that was extremely precious to him and to which he can never return.