I loved this one!

It's the story of "Piranesi", as written in his diary. Piranesi lives in a place he calls the house, which is filled with halls and rooms, no two of which are the same, and with statues all over the place. There are clouds in the upper level of the house, and water in the lower levels, water which sometimes floods the middle levels. As far as Piranesi knows, he has alwas lived in the house, and the only other person we meet is the Other, who meets with Piranesi once a week, but who's whereabouts the rest of the time are unknown.

The quickly suspects things are not quite as Piranesi describes them, and the rest of the plot consists of Piranesi finding his place in the world again.

I loved the prose and the setting of this one, and there were a number of callouts to C. S. Lewis' works, which thematically fit the work really well.