The wall in question might be a bit difficult to find for the casual tourist
. I decided one rainy afternoon in Prague to simply wander off the beaten track
a bit and see what I could find.
I stumbled across this wall quite by accident and judging by the absence of gawking tourists photographing it, it's not exactly a hot location for visitors to Prague.
From memory if you wander over Charles Bridge toward the Prague Castle, go about 500 meters up the hill, turn left and walk parallel to the river for a short while then turn left and walk toward the river again, you'll find it.
Walking through the less "touristy" parts of Prague is an amazing experience. If you're going to Prague make an effort to just wander.
I love Prague. You must go there.