The Queluz gardens were designed by the French architect and silversmith Jean Baptiste Robillion. The two upper gardens are both mutually separated and divided from the rest of the park by balustrades decorated with stone sculptures.

The Malta Garden, smaller in size (built on the site of a former water mirror feature), in front of the Throne and Music Rooms, was thereby named in honour of the Order of Malta of which Pedro III was the Grand-Master.

The Hanging or Neptune Garden, at the axis of the Ceremonial Façade, derives its name from being partially located over a reservoir that gathers any excess waters from the two large lakes flowing into it: Neptune’s Lake and the Amphitrite or Nereid’s Lake. The decoration of the geometric flowerbeds, defined by boxwood bushes, suggests a “parterre de broderie” in the French style. The entire set is decorated with lakes, vases, urns and statues in marble, with most acquired from Italy, and lead sculptures that came from the London workshop of John Cheere, which predominantly adopt themes interrelated with classical mythology.