Williamsburg is accessed by Pennsylvania Route 866, approximately fifteen miles from Altoona to the west and thirteen miles from Huntingdon to the east. The streets are laid out in a grid pattern; going from the Juniata River southward are First (or Front) Street, Second Street, Third Street, and Fourth Street (east side of the borough only). Union Street and Academy Alley/Sage Hill Drive follow the same direction of Fourth Street, if it continued. The main street is High Street, which runs through the center of the borough. Going east from High Street are Spring, Liberty, and Locust Streets; going west are Plum, Black, and Taylor Streets, with Dean Street just over the municipal line in Woodbury Township.