St. Marx Cemetery is one of my favourite places in Vienna (for all those, who wonder about the name: Marx is an old form of Markus). The cemetery was in use from 1784 until 1874. Since the 1930ies it is under monumental protection and preserved in its original form. It is most famous for Mozart's grave (although his remains later were transferred to the Central Cemetery). The best seasons to visit are late April/early May, when the lilac is blooming and in autumn.