The Citadel of Calais was built between 1560 and 1571 on the site of a former medieval castle which was built in 1229 by Philippe de Hureprel. Its purpose of its construction was to fend off would-be invaders, but it wasn't long until the city was successfully invaded by Archduke Albert of Austria on 24 April 1596. Both Louis XIII and Cardinal Richelieu at one time considered expanding the citadel and Calais into a great walled city for military harbour purposes but the proposals came to nothing.
References:The Jan Hus Memorial stands at one end of Old Town Square. The huge monument depicts victorious Hussite warriors and Protestants who were forced into exile 200 years after Hus, and a young mother who symbolises national rebirth. The monument was so large that the sculptor designed and built his own villa and studio where the work could be carried out. It was unveiled in 1915 to commemorate the 500th anniversary of Jan Hus' martyrdom. The memorial was designed by Ladislav Šaloun and paid for solely by public donations.
Born in 1369, Hus became an influential religious thinker, philosopher, and reformer in Prague. He was a key predecessor to the Protestant movement of the sixteenth century. In his works he criticized religious moral decay of the Catholic Church. Accordingly, the Czech patriot Hus believed that mass should be given in the vernacular, or local language, rather than in Latin. He was inspired by the teachings of John Wycliffe.