Monmouth Manufacturing is described as having a brick exterior except for the east-end which has the words Monmouth Manufacturing on the wall. It is built in an overgrown concrete lot that takes up the whole block of land and is gutted and black-eyed.
It also has twenty five foot ceilings and wide open spaces. Neither Gansey or Adam have any idea about what the factory used to manufacture although it does have gouged brick walls and moisture stains on the floor. It smells like the good dusty smell of old books and the first story does indeed have nothing but dust, dirt and concrete.
The second story is where the boys live and has two rooms to house Ronan and Noah (and briefly Adam) while Gansey sleeps in the main room. The floor is cluttered with a cardboard model of Henrietta and the walls have boxes of other information from previous areas Gansey has studied energy and ley lines at.
Blue Sargent says the place reminds her of a messy explorer, an obsessed scholar and a mad inventor combined.