Notre Dame Gate is one of the original seven gates built into the Cottonera Lines by Grand Master Fra Nicola Cotoner in 1670. It was meant to serve as the principal gate for use by traffic emanating from the southeastern towns and villages. Porta Marina served the western part of the lines on the Senglea side.
In its present configuration, it has three gateways: a central one for vehicular traffic and two small ones on either side for pedestrians.
The highest building in Cottonera, the Gate is built on five levels with an elevated gatehouse resting on two large arcaded flanks, each of which were designed to offer bomb-proof cover to anyone taking refuge in them during a raid. The architectural style of this building is impressively ornate, following the high Baroque style of the time.