The Red Rec (the park in Weatherfield) is so called because it's a 'red brick recreation ground'. In the picture on the right of the real park where they film most (but not all) Red Rec scenes you'll see the park has high brick walls. In fact, under the park is a reservoir.
The first wedding filmed on location was Harry Hewitt's. It was filmed at St Clement's in Ordsall. The church is still there. The road leading up to the church was Archie Street, and this was used for occasional outdoor street scenes. Archie St is long gone though the name lives on.
Just up the road from the Red Rec location used to be a cinema. Actress Violet Carson played the piano there for the silent films, long before Coronation Street had been invented.