For today's Geo Quiz, we're looking for the birthplace of a literary giant. The opening sentence of the author's most famous work is your first clue.

It reads -- "As Gregor Samsa awoke one morning from uneasy dreams, he found himself transformed in his bed into a gigantic insect."

In another of his novels, the author describes a bank clerk who wakes up and -- for reasons he can never figure out -- is arrested and enmeshed in a hopelessly absurd judicial process.

The author of those works has been deceased for eight decades. His birthplace is a European capital. Tourists flock to its historic center to stroll in the Old Town and to visit its medieval castle. In fact, one of our mystery author's novels is titled "The Castle."

We'll accept two answers -- the name of the author -- or the name of the city.

You choose.