If you like small hotels, which abound in Europe, I can personally recommend the Soggiorno Battistero in Florence -- five rooms on the fourth floor (walk up) -- with a great view of the Baptistery. If you like narrow hotels, there is the Hotel Clementin in Prague which is almost eleven feet wide -- only three of the nine rooms are in the original building facing the street, but there is an elevator (tiny) and the Charles Bridge is just around the corner.
These are both very romantic locations.