5 Best Sights in Estremadura and the Ribatejo, Portugal

Dedicated to "Saint Mary of Victory," this UNESCO World Heritage Site was built to commemorate a decisive Portuguese victory over the Spanish on August 14, 1385, in the Battle of Aljubarrota. In this engagement the Portuguese king, João de Avis, who had been crowned only seven days earlier, took on and routed a superior Spanish force. In so doing he maintained independence for Portugal, which was to last until 1580, when the crown finally passed into Spanish hands. The heroic statue of the mounted figure in the forecourt is that of Nuno Álvares Pereira, who, along with João de Avis, led the Portuguese army at Aljubarrota.

The monastery, a masterly combination of Gothic and Manueline styles, was built between 1388 and 1533. Some 15 architects were involved in the project, but the principal architect was Afonso Domingues, whose portrait, carved in stone, graces the wall in the chapter house. In the great hall lie the remains of two unknown Portuguese soldiers who died in World War I: one in France, the other in Africa. Entombed in the center of the Founder's Chapel, beneath the star-shape, vaulted ceiling, is João de Avis, lying hand in hand with his English queen, Philippa of Lancaster. The tombs along the south and west walls are those of the couple's children, including Henry the Navigator. Perhaps the finest parts of the entire project are the Unfinished Chapels, seven chapels radiating off an octagonal rotunda, started by Dom Duarte in 1435 and left roofless owing to lack of funds. Note the intricately filigreed detail of the main doorway.

Like the monastery at Mafra, the Mosteiro de Alcobaça was built as the result of a kingly vow, this time in gratitude for a battle won. In 1147, faced with stiff Muslim resistance during the battle for Santarém, Portugal's first king, Afonso Henriques, promised to build a monastery dedicated to St. Bernard and the Cistercian Order. The Portuguese were victorious, Santarém was captured from the Moors, and shortly thereafter a site was selected. Construction began in 1153 and was concluded in 1178. The church, the largest in Portugal, is awe-inspiring. The unadorned, 350-foot-long structure of massive granite blocks and cross-ribbed vaulting is a masterpiece of understatement: there's good use of clean, flowing lines, with none of the clutter of the later rococo and Manueline architecture. At opposite ends of the transept, placed foot to foot some 30 paces apart, are the delicately carved tombs of King Pedro I and Inês de Castro.

The graceful twin-tiered cloister at Alcobaça was added in the 14th and 16th centuries. The Kings Hall, just to the left of the main entrance, is lined with a series of 18th-century azulejos illustrating the construction of the monastery.

One of the largest Catholic churches in the world, seating some 8,500 worshipers, the Holy Trinity was consecrated in 2007 and raised to the state of basilica in 2012. Although it won prizes for engineering rather than architecture, its ample, curved form—designed by Greek architect Alexandros Tombazis—offers a pleasing contrast to its rather run-of-the-mill 1920s predecessor. Much of the iconography, including on the lavish main doors, was inspired by Byzantine and Orthodox motifs, and was produced by artists from Portugal and seven other countries. The Tall Cross crucifix outside the church is by the German artist Robert Schad.

At the head of the shrine's huge esplanade is the towering neoclassical basilica built in the late 1920s, flanked on either side by a semicircular peristyle. Inside you will find the tombs of all three of the "little shepherds" who saw the Virgin Mary.

This tiny chapel—now ringed by benches and covered by a much larger modern canopy—was built in 1920 on the site where the appearances of the Virgin Mary are said to have taken place. A plinth with a statue of the Virgin marks the exact spot. Gifts, mostly wax reproductions of body parts, are burned nearby as offerings to the Virgin in the hope of achieving a miraculous cure.