The New Town Hall was built in the late 14th century, when the New Town was still new. From the window of the main hall (the tower was not built until 1456), two of Wenceslas IV’s Catholic councillors were flung to their deaths in 1419 by followers of the Hussite preacher Jan Želivský, sparking off the Hussite Wars.
This event gave ‘defenestration’ (throwing out of a window) a lasting political meaning, and a similar scenario was repeated at Prague Castle in 1618. You can visit the Gothic Hall of Justice, which was the site of the defenestration, and climb the 221 steps to the top of the tower.