Porta Appia was the northern gate which gave access to the town through Via Appia. Today only its ramparts are still visible.

The gate was probably built between 1460 and 1472 under the governing rule of the Manfredi family.

Porta Appia was part of the "Cinta Manfrediana" (Manfredi Walls) surrounding Imola. This gate was originally named "del Piolo" because of the kerbstone which prevented carriages from entering the town.

The gate's scarp ramparts were connected together and surrounded by a moat. The ramparts underwent restoration work for residential purposes. They now stand in the middle of 19th century houses.