Sure. There could be a 'arch fanfic' where a group of friends decide to restore an old arched bridge that has a legend associated with it. As they work on the restoration, they start to experience strange occurrences, like seeing apparitions of the bridge's original builders. Or perhaps a fanfic where an artist is inspired by the arches in a particular building and creates a series of paintings that come to life, and the story follows the chaos that ensues in the art world because of these living paintings.
One example could be a fanfic where the main character is an architecture student who stumbles upon a magical blueprint in an old attic. This blueprint leads to a series of adventures in different architectural wonders around the world. Another example might be a story set in a post - apocalyptic world where the only remaining structures are ancient arches, and the characters must decipher their secrets to survive.