Gothic architecture
Sens Cathedral (begun between 1135 and 1140) was the first Cathedral to be built in the new style (St. Denis was an abbey, not a Cathedral). Other versions of the new style soon appeared in Noyon Cathedral (begun 1150); Laon Cathedral (begun 1165); and the most famous of all, Notre-Dame de Paris, where construction had begun in 1160.
Portuguese Romanesque architecture
Thus, in Portugal, the strong presence and popularity of Romanesque until later centuries meant that this decorative and architectural Cistercian model was the perfect basis for the slow change into Gothic style, without never completely cutting off with the previous Romanesque. Instead, these two styles merged in Portuguese architecture like nowhere else in Europe within a specific kind called Mendicant Gothic, typical of monastic buildings. Alcobaça, one of the biggest Cistercian abbeys in the world, is the first fully Gothic building in Portugal, but it still has a heavy and austere exterior appearance, only balanced by its tall and massive rib vaulted central nave and aisles. Churches like Santa Maria dos Olivais in Tomar, or São João de Alporão in Santarém are perfect examples of this Mendicant transitional period between the Romanesque and the definitive settle of Gothic style, which would only be a reality by the 14th and 15th centuries.