Portugal has 15 world heritage sites including: Douro wine region, Angra do Heroísmo, Convent of Christ, Sintra, Garrison Border Town of Elvas and its Fortifications, Évora, Guimarães, Porto, Landscape of the Pico Island, Macaronesia and the Mediterranean Basin, Alcobaça Monastery, Monastery of Batalha, Jerónimos Monastery, Prehistoric Rock-Art Site of the Côa Valley, and the
University of Coimbra.

https://en.wikipedia.org/wiki/List_of_World_Heritage_Sites_in_Portugal

The Tower of Belem is in Lisbon [Lisboa], Portugal's capital city. Along with nearby Monastery of the Hieronymites [Mosteiro dos Jerónimos], the Tower was inscribed as a UNESCO World Heritage Site in 1983. The tower was commissioned by João II [March 3, 1455 - October 25, 1495] for defense and as a ceremonial gateway to Lisbon. It was built, by military architect Francisco de Arruda [d. 1547] from 1515 to 1521, at the mouth of the Tagus River [Rio Tejo] on the Atlantic Ocean . The tower was dedicated to Lisbon's patron saint, São Vicente [St. Vincent of Saragossa, martyred c. 304 AD].

Synonyms for "regularly" include: * frequently * uniformly * periodically * steadily * evenly * continuity * rhythmically * punctually * successive * intermittently * every so often * at fixed interval.