The story of the imprisoned Nun

Re the comment below, this is the story as it is told by the locals (short version):
There is a big monastery with an impressive church right in the middle of the Latran quarter in Krumlov. Now it is back in the Knights of the Cross' ownership, but whether they owned it in those olden times from whence this story comes, I don't know. The church itself is remarkable by its Black Madonna - but I will stick to the story of the Nun.

In her days, there was a nunnery and a monastery right next door to one another, and the nuns and the monks shared the church for the services. They were not allowed to speak or to meet of course, their lives were to be separate, except it would have been hard for the occupants of these fine institutions not to catch glimpses of the other sex out of windows, or indeed on the way to the church. And so our Nun became enamoured of a rather handsome Monk, and he, too, fell in love - but what to do? They managed to exchange glances, or pass a few written notes to one another but their feelings became unbearable, so when an opportunity arose, they took it: once in a while, the monks and the nuns all went to the nearby Kajov church for a pilgrimage - following the route marked by the shrines. The nuns started off first - the monks sufficiently later so as to not be tempted. But once in the forest, our Nun sneaked off the path and waited in the thicket, and when the monks passed by, our monk did the same. The idea was that while all the others were at the service in Kajov, they would have a passionate time together, and then wait for the procession to go back so as to join it again, and no-one would be any wiser. But their passion was so strong they forgot about time - and they were discovered by the nuns returning from the service. The rest of the story is in the post below: - she got walled into the nearest shrine, and he went and rescued her before she died of suffocation or claustrophobia inside. And then, one would like to hope, they ran off, lived happily, and so on...

So the story isn't about an anchorite - though it may have been invented centuries after the shrine was built! This 'shrine' may have well been purpose-made for an anchorite, because it is tall and narrow, and doesn't look like an ordinary shrine-design! Mind boggles :-)