Published in 1818 Endymion is a poem by John Keats. The first line "A thing of beauty is a joy forever" has been often quoted. This epic poem is written in iambic pentameter couplets. The poem is based on the Greek myth of Endymion, the shepherd beloved by the moon goddess Selene. The poem elaborates on the original story and renames Selene "Cynthia". The story begins in a woodland scene. Endymion has a dream in which he loves Cynthia. He then travels to the Underworld in search of his love and in the end they are united.