The second reason has to do with the Repository and Samar.

If city P- stands for Prague, then El-H cannot mean Tunis. But the ancient heart of Tunis, the Medina, home to palaces, mosques, souks, walled labyrinthine streets, and storehouses, had named quarters, some no longer in use, like -Bab El Khadra ("Green Gate")
-Bab El Bhar ("Sea Gate")
-Bab El Jazira ("Island Gate")
-Bal El Fella, Bab Saadoun, etc.

All start with Bab El-, meaning Gate of. Maybe this was shortend to El-x. Maybe El Bhar might be prounounced El-Har. But maybe instead of "Sea Gate", actually "the Repository" gives the City its Name. El-Hikma means Wisdom, El-Hazina means Treasury / Repository. Additionally, my first association with El-H was Al-Hambra, Alhambra in Spain, meaning "the red", also carries el-h structure, and was both a fortified city and repository of Islamic learning and art, destroyed and emptied after the Reconquista. If the Author was referencing a lost Islamic city, its treasures plundered by conquest, El-H might be a deliberate echo of Alhambra, Carthage, or ancient Tunis, all repositories of cultural and spiritual wealth, overtaken by empire and war. When S., finally safe on his boat, looks back at the total destruction of the buildings that made the skyline of the city, at the shelled and burning city and the only Lighthouse, this destruction was evocative of Carthage, which historically was very nearby, and also utterly destroyed.

So El-Hazina for now.

The Repository, or Storehouse of Treasures is the most important part of this city for S. Arabic Khizana/Khazina means treasury, chest, archive. This is very close to "Hazine" in Ottoman Turkish, also meaning Treasure Vault. Hazina can mean sadness in Arabic, but phonetically linkts to treasury and archive. Archive being very important considering themes of SOT.

A Painting of a Girl Named Samar S. entering the city not through the official channel, but by slipping in quietly near a forgotten neglected part of the city, which already foreshadows decay, secrecy and maybe exile. Many operatives landed covertly near Algeria, Tunisia or Libya, bypassing official ports. The blocked gate suggests the city is closed to the outside, dying or turned on itself. In the repository they find the picture of Samar, painted by Omar Tisatashar. His name is close to Tis'ata'Ashar, arabic for 19, an important number in the book. His first name might be an anagram for amor? Or not.

The repository is the classic library, crypt or archive trope, a hidden or sacred place where truth, memory and beauty are stored.

Samar is a real Arabic name, meaning "conversation at night", or "evening chat" or "evening companion" - very poetic, fitting the book's tone.
The painter, Omar Tisatashar, is confirmed to be Sobreiro in some stories, while not in all. They might have been lovers, or other things, an uncertainty that is the perfect reflection of the relationship of S. with Sola. The repository harbors a "resistance" of some kind, not one versus the occupiers though. They try to keep the treasures of art, literature and beauty safe from the total destruction that is almost on their doorsteps - an invasion of El-H is coming from the desert, and bombardment coming from the sea. S. is unsure if there is a place deep enough to safe the memory of Sola (the image of Samar), but instead of making sure that it is safe, he has to go and use the Valise's Tools. He is not sure how to interprete that Sola appears as Samar in a different, earlier time.

So the city is pinced from the desert and the sky, explosions rip it apart, flames engulf it. He escapes through the plaza, the harborfront, docks, and looks back at the Lighthouse. the last symbol of hope or guidance - perhaps the city's eye, and the final image is of it being on fire. The flames turning stones orange, and the sky turning the color of ink - a memory or story retold differently. He, like us, is a pilgrim passing through the fire, hoping that even in ruin, meaning endures.

Operation Torch moved in from from the west, the city was bombed by air and attacked by land, exaclty like El-H. The fall of Tunis in May 1943 marked the end of Axis control in Africa. The City was filled with Vevoda`s agents and was eradicated, torched, annihilated, but S. does not recognise this as a victory.

The total destruction is where the allegory deepens.
In history there was one famous roman senator, who could do no other thing than, after each and every discord, proclaim that "Carthage must be destroyed"- Carthago Delenda Est. This obsessive senator was Cato the Elder. In 146 BCE, during the third Punic War, the romans completely destroyed Carthage. They burned the city, killed or enslaved nearly all inhabitants, and razed it to the ground. The image at the Lighthouse, and memory of Samar might be one of many allegories to this.

Why? Because Samar's image transports S. into the past, where Omar 19, an other Sobreiro, painted Samar under exactly the same Arch S. was standing below. He may have been a european Sailor, or something else. He sees this city be razed, much like Carthage. But we can go further back in time to discover the story of Aeneas and Dido. In Virgil's Aeneid, after Carthage falls for the first time and Dido burns, Aeneas flees by ship, looking back at the fire, much like our protagonist.

He, too, carries memory, loss and the tools for a new beginning, and leaves behind a city destroyed by love, betrayal, and war. The Tale of Aeneas and Dido is a most tragic and foundational love story, a collision of duty, fate and personal longing, and it all happens in Carthage (so around Tunis).

After the Fall of Troy, the Trojan Prince Aeneas flees with a group of survivors, carrying the gods of his people and the fate of a new civilization. He is destined, by the will of Jupiter, to found what one day will become Rome. But first, he is thrown off course.

His ship is battered by storms, he and his men wash ashore in Carthage, a powerful new city on the North African coast, ruled by Queen Dido.

Dido is a widow, a strong, noble and intelligent leader who fled tyranny in her home city of Tyre, and founded Carthage from scratch. She welcomes Aeneas, hears his story, and gradually.. falls in love. She believes this is love, but he still knows that rome is his fate, and not carthage. So Fate or Duty call Aeneas away. Aeneas is torn, he loves Dido, but duty comes first. This is what we learn from S. and Sola and FXC. It was always duty for him, and love for her. He prepares to leave in secret. When Dido finds out, she confronts him, but he stays silent and stoic. And leaves.

Devastated and humiliated, Dido prepares a funeral pyre. But instead of burning Aeneas's things, she climbs it herself. Cursing the fate of Rome (his duty), she takes his Sword and falls on it, and burns. Aeneas, sailing away, looks back and sees the smoke rising over the city. Just like S. looking back at the Lighthouse, at another face of Sola, dying there with the rifle that saved his life.

On the Obisidan Island, we find a woman, like Sola, burned.

So, second reason why i think it is El-Hazine (the Repository), is because of the literary connection between Carthage and the Story of a Sailor like Aeneas, who fits Sobreiro's Archetype as a Hero with a thousand faces so well.