The National Museum is such an impressive and grand building from the outside (and inside) that once during WWII when Prague was under siege, the attackers actually shot the building thinking it was a government building. You can still see the shot-marks on the pillars (white marks)
DUring the severe floods of 2002, various countries in Central Europe were badly flooded. Here was an exhibition about the terrible damage done to Prague
Jan Nepomuk is the patron saint of the Czech Republic. Legend has it if you rub the gold plate at the base of his statute, you will return to Prague again. Lonely Planet writes that the easiest is to buy a return ticket to Prague.