We will start outside outside Cafe Kafka, in Franz Kafka Square. You can reach it from the Old Town Square by walking towards the river. On the train, disembark at Staroměstská metro station and walk about 200 metres away from the river.
Directions from the end point to Kafka's Grave:
I'll leave you at Malostranská metro station. Climb down to the platform and take the train on your left hand side, where the incoming trains face towards you. The station where you need to get off is called “Želivského”. If that's a little complicated, here is an easier hint: It is one stop after the station “Flora”. Once you disembark, climb up to street level. In one corner of the intersection, you'll find the entrance to the Jewish cemetery. Inside the compound, make a sharp right and walk some five minutes along the enclosing wall. Kafka's grave is located at the big white sign with the number “21”.