Which descriptive details of the interior of the house suggest that the narrator has entered a realm that is quite different from the ordinary world?

The narrator describes the house in The Fall of The House of Usher as being "gothic" and slightly scary which gives the reader the sense that the narrator has entered a realm that is "different". Also the country neighborhood thereabouts, along the dusty roads, one found at intervals the prettiest little cottage homes, snug and cozy, and so cobwebbed with vines snowed thick with roses that the doors and windows were wholly hidden from sight etc...