This door leads into the city of Leiria, and, unlike other doors, this one never closes.
A walk through it provides access to a huge range of art forms, culture, entertainment, leisure, commerce and cuisine.
The A Porta Festival is a facilitator of meetings, a bringing together of sorts, an event for everyone, especially for the local population.
A Porta is held in June every year, providing music, visual arts, workshops, themed dinners and over 1001 other doors.
Find out more at the A Porta Festival website.