At the place where the Kamenický stream meets the Sázava river, you can visit the mysterious ruins of the royal castle demolished Kostelec. The ruins are part of a nature reserve and are freely accessible.
The castle was probably founded in the last third of the 13th century by King Wenceslas II, but the first written mention dates back to 1342, when it was held in pawn by Oldřich Medek of Valdek. Although Charles IV bought back the castle in 1356, he soon pawned it again and it had several owners over time. The last of them was Kuneš Rozkoš of Dubá from 1443, who looted in the surrounding area, and therefore the castle was besieged in 1449. It withstood this siege, but a year later, on May 18, 1450, it was besieged again and five days later it was conquered by the army under the command of Zdeněk Konopišťský of Šternberk, who became its new owner. In 1456, serfdom was abolished and he fortified it as one of his military strongholds. Later, he became a leading figure of the anti-Poděbrady opposition, and therefore the royal army captured and destroyed the castle in 1467.
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.