If you're spending some time in Saint-Jean, Perpignan Cathedral and Republic Square are top sights worth seeing.
Though La Gare may not have many top sights, you can venture to the surrounding area to see attractions like Le Castillet and Republic Square.
When in Les Platanes, you can plan a visit to Palais des Congres and Perpignan Cathedral, some noteworthy sights in the nearby area.
When in Moulin à Vent, you can plan a visit to Palace of the Kings of Majorca and Republic Square, some noteworthy sights in the nearby area.
When in Clémenceau, you can plan a visit to Le Castillet and Republic Square, some noteworthy sights in the nearby area.