La Tour (1987) by François Schuiten and Benoît Peeters is the third story in the Cités Obscures series, although it’s the fourth volume if you want to be strictly canon about things, L’archivist, a guide to places in the Obscure World, having preceded it.
Carcere Oscura by Piranesi (1750).
This is another book where Schuiten and Peeters’ interests tick a list of my own obsessions, being a tale which seems to originate in the question “What would it be like if you crossed Piranesi‘s Prisons etchings with Bruegel’s Tower of Babel?” The protagonist of La Tour, Giovanni Battista, has his name borrowed from Piranesi’s forenames and his appearance taken from Orson Welles’ Falstaff in Chimes at Midnight. The story owes something to Kafka, although it lacks Kafka’s drift towards paradox, concerning a colossal building referred to throughout as The Tower, a structure we only ever see in close-up—and then mostly from the inside—but whose height must reach several thousand feet.
Battista (above) is one of the Keepers, a group of men charged with maintaining small sections of the Tower whose structure suffers continual decay and collapse. Tired of years spent in complete isolation, and concerned that other Keepers aren’t doing their job, Battista goes in search of the Tower’s feared Inspectors, only to discover that the lack of maintenance is endemic and few of the Tower’s scattered residents have any idea of the origin or purpose of the vast building where they’ve spent their lives, never mind a concern for its upkeep. There are no Inspectors, and while Battista is worried at the beginning about vines in the stonework, we later see small forests growing among the ruins. Kafka resonances come with the mention of the mysterious Base, and the equally mysterious Pioneers, those builders and engineers who went ahead years or even centuries before, climbing skyward.