Sherbourne and Wellesley are the names of two different streets in Downtown Toronto (Canada). When two different street names are connected with and in the middle, it can generally be identified as an intersection. Sherbourne and Wellesley is a way of shortening the intersection at/between Sherbourne and Wellesley.
Ex: There's a great cafe I go to at Yonge and Bloor.
Ex: My office is near Sherbourne and Wellesley.