"La Belle Dame sans Merci" by John Keats exemplifies many of the typical features of Romantic poetry.
First, it is written in the form of a traditional ballad, a literary genre that was frequently used by Romantic poets. The poem uses a form of ballad meter, being written in quatrains rhymed ABCB, with the first three lines of each quatrain usually in iambic tetrameter and the fourth line in iambic dimeter.
The setting of the poem is medieval, echoing the "gothic" or medieval revival of the Romantic period. While Augustan authors had disparaged medieval culture as rude and barbaric, the Romantics found inspiration in the very sense of irregularity and mystery that the rational Augustans disliked. Instead, the Romantics saw medieval folklore and romance as a necessary counterweight to what they felt was the soullessness and inhumanity of an urban life transformed by the Industrial Revolution.
The pastoral setting is also typical of Romantic poetry, as is the theme of unrequited love.