From Halopedia, the Halo wiki
Gladsheim Main Street was a stretch of road running the length of the city Gladsheim on the human colony world Harvest.
Gladsheim Main Street was described as "ten blocks of brightly painted, flat-roofed stores and restaurants as well as a modest three-story hotel".
Sergeant Avery Johnson compared the buildings on main street to books in a bookshelf, as they appeared to be packed more tightly than they were.
This is potentially due to the buildings appearing closer together than the widely spread JOTUN repair shops and farm-supply warehouses placed in a grid to the east of the main street.