This gem of a timepiece has lots of legend attached to it.  One legend has it that it was built by Master Hanus.  He was paid well by the Prague councillors but when they realized that the clock was so exceptional and that other towns would want one, they blinded him.  This backfired when the clock needed repaired.  Eventually someone was found who could repair it and to this day crowds gather when the clock strikes the hour.  It tells date, year et cet as well as the time.