The Cidadela, the Nossa Senhora da Luz Fortress and the Tower, are part of the military fortitudes built between the 15th and the 17th centuries along the Tagus estuary for the Lisboa’s coastal defence from the French and English troops and piracy.
In 1871, part of the structures of the Cidadela are adapted and transformed into a Summer Residence of the Royal family that started to choose the Cascais coast because of the medical benefits of its waters.
In the garden there is an interesting small open-air artillery museum.