The only one of La Ruta de Cister's monasteries to be declared a UNESCO World Heritage site, for its majestic appearance and size and the beautiful artistry of its cloisters, as well as the tombs of the kings and queens interned there is the Royal Monastery of Santa María de Poblet, where you'll spend the morning, and which is still home to a community of nuns.
The monastery is fronted by the Plaça de la Corona d'Aragó, which opens to the impressive sight of the building itself, with its two central hexagonal towers, more suited to a castle than a monastery, that flank the Porta Reial. Once inside, you'll enter the cloister, an excellent presentation of a perfect living art-history lesson, displaying the differences between the Romanesque and the Gothic styles. The cloister leads to all the chambers where you can marvel at the beautiful architecture. The monastery was begun halfway through the 12th century when Ramón Berenguer IV conquered the land, and has witnessed both splendid and destructive times in its history. Today it is full of light. In the church you can see the magnificent 16th-century alabaster altarpiece, and the tombs of the eight kings and six queens of the Crown of Aragon who have lain here for centuries.
Afterwards, head to Vimbodí, about five kilometres away, where you can visit a glass museum and see for yourself how glass is made. The space is open from 10am to 2pm.