The Fronteira Palace, also known as the Palace of the Marquesses of Fronteira, is the privately owned property, but parts of it are opened to visits, and only on a tight schedule.
The palace was built in 1640 for the first Marquis of Fronteira, Dom Joao de Mascarenhas (bestowed with the title of Marquis of Fronteira for his allegiance to King Pedro II of Portugal), in order to serve as hunting pavilion. At present, the oldest part of the castle complex refers to a 16th century chapel, but inside the castle, visitors can admire the stunning Battle Room (which stands out by the splendid tile panels due to which the room has been dubbed the Sistine Chapel of Tile Panels), as well as the Dining Room (with highlights like the paintings signed by Domingos Antonio de Sequeira). Outside the castle, visitors can search out the carefully arranged garden, which fills a surface of some 5.5 hectares, offering the spectacular scenery of the ingeniously cut hedges, tile panels and a statuary where sculptural works rendering the Kings of Portugal (chiefly, busts) are displayed.