Lentorama 2026: Hic es: aedificia Vaticani 

Day 36: Leonine Wall

In 846, Arab raiders in Rome sacked the original St. Peter's Basilica. It, like much of the territory that today makes up the Vatican city state, was outside of Rome's protective walls.

In order to prevent any future sacking, Leo IV decided to enclose St. Peter's and the surrounding area in its own wall, which he built between 848 and 852 (Leo III had previously started a wall, but it faced several delays and was largely dismantled by locals who wanted to use the stone for their own buildings).

Today, there are still bits of the wall standing, most notably in the Vatican gardens by the Vatican Radio transmitter. These parts of the wall are anchored on the Torre San Giovanni, which as previously noted was added later to bulk up Vatican defenses.

  Lentorama 2026: Hic es: aedificia Vaticani 

Day 35: Sacristy, St. Peter's Basilica

Like I said, more on this, but not much more.

The current sacristy was the idea of Pope Pius VI, who laid its cornerstone in 1776, and saw it inaugurated in 1784. It stands on the place of the old sacristy, though some additional buildings were demolished so architect Carlo Marchionni could build the new one at an appropriately monumental scale.

The sacristy is connected to the basilica by two covered walkways, one enters into a side chapel while the other is near the tomb of Pius VIII. 

  Lentorama 2026: Hic es: aedificia Vaticani

Day 34: Biblioteca Apostolica Vaticana, Cortile Belvedere

The origins of the Apostolic Library go back to the 4th century, when there is documentary evidence of  a combined library and archive. But there wasn't a specific, permanent collection until the 15th century, when Pope Nicholas V made the decision to create a formal library and Sixtus IV saw the plan through. Starting with a collection of 1200 manuscripts in Latin, Greek, and Hebrew, the collection would grow over time, with a collection today of over 1.1 million books and 75,000 codices.

The library is still located in its original building, which is now considered part of the Apostolic Palace complex. Its most notable contribution to Vatican architecture was its bisecting of the Belvedere Courtyard, created by Donato Bramante in the early 16th century. The courtyard was originally intended as one long enclosed space running from the Apostolic Palace to the Villa Belvedere. But a new wing for the library ordered by Sixtus V saw the courtyard cut into two pieces (now three, with the Pigna Courtyard, a small library courtyard, and the remaining Belvedere Courtyard).

While I feel bad for Bramante that his original vision was permanently altered, he at least didn't live to see it happen. It also could be worse; he could have lived to see that, today, his courtyard is used as a parking lot.

 Lentorama 2026: Hic es: aedificia Vaticani

Day 33: Palazzo della Canonico

I still don't know much about this building, which is located right next to the sacristy of St. Peter's (more, but maybe not much more, about that later). It doesn't help that there are other buildings by this name in Italy, most notably (based on the number of hits) in Pisa.

The best that I can tell is that this was built for the canons of the basilica by Pius VI. which would put its construction in the last quarter of the 18th century. Other than use by the canons, it was also the home of the basilica's archives for a time (most of the archive was relocated to the Vatican Library in 1940).

More recently, the building became home to the School of Arts and Crafts of the Fabric of Saint Peter, which will teach skills like masonry, plastering, and carpentry to students who will then use their skills to maintain the basilica (the mission of the Fabric). 

One map I've been consulting for this suggests that the building is also the home to the Treasury of St. Peter, a museum of historical liturgical artifacts used in earlier iterations of the basilica. But the descriptions I've found online make it sound like the museum is housed in the basilica (or the sacristy) itself.

Lentorama 2026: Hic es: aedificia Vaticani

Day 32: Domus Sanctae Marthae, Piazzza Santa Marta

The House of Saint Martha takes its name from Martha of Bethany, sister of Lazarus. The Bible stories with Martha show her as being focused on the duties of the household and towards her guests, as opposed to her sister Mary, who "has chosen what is better" by ignoring those duties and only paying attention to Jesus and his teaching.

Over time, as Martha became venerated, the stories were transformed into positive qualities of common sense, maturity, and care for others. So it's not surprising that when John Paul II decided to build a place where visiting clerics could stay when visiting the Vatican, he chose to name it after Martha. 

The domus was built on the site of the former St. Martha Hospice, built in 1891 by Leo XIII to treat patients of an expected cholera outbreak. When that didn't happen it took in the sick from part of Rome, as well as pilgrims who fell ill. Over time it began to house displaced persons and, increasingly, Vatican staff.

JP2's primary motivation for building the domus, though, was to give cardinals a place to stay during conclaves. Previously they stayed in temporary rooms in the Apostolic Palace, which were lacking in comfort and amenities (as JP2 experienced himself in two conclaves). The five story building, located next to the Palazzo San Carlo and steps from St. Peter's, was completed in 1996. It would be used for a conclave for the first time after John Paul's death.

The domus may be best known as the home for Pope Francis during his tenure in office. He opted to stay in the domus rather than move to the papal apartments as he wanted to live with others rather than in the solitude the apartments would provide. This arrangement is also seen in the movie Conclave, where the recently deceased pope is shown living in the same building that the cardinals inhabit during the vote to replace him.

 Lentorama 2026: Hic es: aedificia Vaticani

Day 31: Grotta di Lourdes, Viale Benedetto Quindicesimo

In 1854, Pope Pius IX promulgated the dogma of the Immaculate Conception, the idea that Mary was free of original sin from the moment of her conception. This idea was the basis of a series of visions a few years later by Bernadette Soubrious, who reported 18 visitations by Mary in a grotto near Lourdes, France.

The construction of replica grottoes became popular after that, with Leo XIII deciding the Vatican needed one of its own.  Built in the Vatican Gardens along the wall to St. John's Tower, it was presented to Leo in 1902 but formally consecrated in 1905 by Piux X.

The grotto was built with a spire and two staircases to reach it, but all of that was removed by Pius XI and John XXIII for safety reasons. The grotto is often the site of a papal mass at the end of May, a month dedicated to Mary by the church.

Lentorama 2026: Hic es: aedificia Vaticani

Day 30: Heliport, Viale Pio XI

Not a building per se, but in the interest of transportation completeness let's throw it in. The Vatican heliport is a concrete slab with parking tucked into the westernmost bastion of the Leonine Wall. It was built in 1976 by Paul VI to facilitate trips between the Vatican and Castel Gandolfo, as travel by car could take up to two hours one way.

The heliport is also occasionally used to get visiting dignitaries to the Vatican from Rome's airport. It can also be used for medical transport to the Bambino Gesu Hospital, a pediatric hospital in Rome that was donated to the Vatican and is under its extraterritorial jurisdiction.