You please consider there is a junction of Main Street and Second Avenue. Which ones are correct?
1. It's at the corner of Main Street and Second Avenue.
2. It's at the corner of Main and Second.
3. It's at the corner of Main and Second Street.
4. It's at the corner of Main and Second Streets.
5. It's at the corner of Second and Main Avenue.
6. It's at the corner of Second and Main Avenues.

7. Replacing 'at' with 'on' in the above sentences.