To find and collect all the notes in Vatican City in “Indiana Jones and the Great Circle,” you need to explore various locations within the Vatican and solve specific puzzles or complete side quests. Here is a detailed list to help you locate and collect all the notes:

### Field Notes
1. **Clerical Key Required**
– **Location:** The Vatican – Post Office
– **Note:** Catherine’s Letter
– **Instructions:** Use the Clerical Key to enter the main hallway. The letter is on a small cart with a lamp.

2. **No Requirements**
– **Location:** The Vatican – Apostolic Palace
– **Note:** Cleaning Note
– **Instructions:** From the courtyard, climb up scaffolding behind the large billboard in the south part of the plaza. Climb a second set of scaffolding to enter the Apostolic Palace. The note is on a large marble display across from the window.

3. **No Requirements**
– **Location:** The Vatican – Apostolic Palace
– **Note:** Ipeo Card
– **Instructions:** In the western part of the Apostolic Palace, there is a large open room with two floors and a large chandelier. The note card is sitting on a small red bench at the end of a hall.

4. **No Requirements**
– **Location:** Vatican City – Sistine Chapel
– **Note:** Nicoletti’s Letter
– **Instructions:** Located in an office on the west end of the Sistine Chapel, sitting on a small table.

5. **No Requirements**
– **Location:** Vatican City – Apostolic Library
– **Note:** Ventura’s Letter
– **Instructions:** This letter appears on Antonio’s desk after speaking with Sister Catherine in the Sistine Chapel.

6. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Code Look Up Table
– **Instructions:** In the Museum wing, there is a large open garden section filled with enemies. The note is in a tent in the southeast area, along with other notes on a desk and one in the drawer.

7. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Secret Delivery Letter
– **Instructions:** Same location as the Code Look Up Table.

8. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Calendar Page
– **Instructions:** Same location as the Code Look Up Table.

9. **Safe Code Required**
– **Location:** Vatican City – Museum Wing
– **Note:** Giovanni’s Letter
– **Instructions:** In the Museum wing, there is a locked case. Use the notes to figure out the code (6380) to open it, and the note is inside.

10. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Gina’s Note
– **Instructions:** In the Museum Wing storeroom, this note is on a wooden case across from a bloody handprint.

11. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Identification Card
– **Instructions:** In the Museum Wing storeroom, this note is on the floor between two metal grates.

12. **Advance the Mystery Required**
– **Location:** Vatican City – Borgia Tower
– **Note:** Interrogation Document
– **Instructions:** At the top of Borgia Tower, enter the room where Guiliana is being interrogated. The note is on a chair in the corner.

13. **Complete A Nun in Trouble Mystery Required**
– **Location:** Vatican City – Borgia Tower
– **Note:** Italian Poem
– **Instructions:** After completing the mystery, you will be given Guilana’s key. Head back down Borgia Tower until you find a gap that must be crossed by swinging with the whip. Open that door with the key and open a second door immediately to the right. Inside there is a small office, and the note is in the desk drawer.

14. **Finish A Nun in Trouble Required**
– **Location:** Vatican City – Sistine Chapel
– **Note:** Mother-in-Law’s Letter
– **Instructions:** Return to the Sistine Chapel after completing A Nun in Trouble and seeing the cutscene where a fascist asks Indy to do confession. The letter from the fascist’s mother-in-law will be on ground outside the Confession Booth.

15. **No Requirements**
– **Location:** Vatican City – Sistine Chapel
– **Note:** Hidden Note
– **Instructions:** Open the Secret of Secrets safe (4471) to find the note inside, in the west end of the Sistine Chapel.

16. **No Requirements**
– **Location:** Vatican City – Belvedere Courtyard
– **Note:** Tales of Dread #2
– **Instructions:** In the restricted Blackshirts area, this comic is on a desk in one of the smaller tents. The Blackshirts Disguise makes this easier to obtain.

### Mystery Notes
1. **No Requirements**
– **Location:** Vatican City – Apostolic Palace
– **Note:** Cleaning Note
– **Instructions:** Same as Field Note instructions.

2. **No Requirements**
– **Location:** Vatican City – Apostolic Palace
– **Note:** Ipeo Card
– **Instructions:** Same as Field Note instructions.

3. **No Requirements**
– **Location:** Vatican City – Sistine Chapel
– **Note:** Nicoletti’s Letter
– **Instructions:** Same as Field Note instructions.

4. **No Requirements**
– **Location:** Vatican City – Apostolic Library
– **Note:** Ventura’s Letter
– **Instructions:** Same as Field Note instructions.

5. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Code Look Up Table
– **Instructions:** Same as Field Note instructions.

6. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Secret Delivery Letter
– **Instructions:** Same as Field Note instructions.

7. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Calendar Page
– **Instructions:** Same as Field Note instructions.

8. **Safe Code Required**
– **Location:** Vatican City – Museum Wing
– **Note:** Giovanni’s Letter
– **Instructions:** Same as Field Note instructions.

9. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Gina’s Note
– **Instructions:** Same as Field Note instructions.

10. **No Requirements**
– **Location:** Vatican City – Museum Wing
– **Note:** Identification Card
– **Instructions:** Same as Field Note instructions.

11. **Advance the Mystery Required**
– **Location:** Vatican City – Borgia Tower
– **Note:** Interrogation Document
– **Instructions:** Same as Field Note instructions.

12. **Complete A Nun in Trouble Mystery Required**
– **Location:** Vatican City – Borgia Tower
– **Note:** Italian Poem
– **Instructions:** Same as Field Note instructions.

13. **Finish A Nun in Trouble Required**
– **Location:** Vatican City – Sistine Chapel
– **Note:** Mother-in-Law’s Letter
– **Instructions:** Same as Field Note instructions.

14. **No Requirements**
– **Location:** Vatican City – Sistine Chapel
– **Note:** Hidden Note
– **Instructions:** Same as Field Note instructions.

15. **No Requirements**
– **Location:** Vatican City – Belvedere Courtyard
– **Note:** Tales of Dread #2
– **Instructions:** Same as Field Note instructions.

### Discovery Notes
These notes are not specifically listed but are mentioned as part of the overall note collection in Vatican City. You can find these by exploring various areas of the Vatican, including libraries, museums, and other locations.

### Adventure Notes
These notes are also not specifically listed but are part of the overall note collection. They are related to the main objective and can be found by exploring different areas of the Vatican.

### Photos
In addition to physical notes, you can also take photos of different points of interest in Vatican City. These photos count towards the same total as physical notes and can be found by exploring various locations and taking snapshots for Father Antonio.

### Collecting Notes
To collect all the notes, follow these general steps:
1. **Explore the Vatican:** Start by exploring the various areas of the Vatican, including the Post Office, Apostolic Palace, Sistine Chapel, and Museum Wing.
2. **Complete Side Quests:** Complete side quests like A Nun in Trouble to unlock specific notes.
3. **Solve Puzzles:** Solve puzzles to unlock safe contents.
4. **Use Keys and Codes:** Use keys and codes to access locked areas and safes.
5. **Take Photos:** Take photos of points of interest to contribute to your overall note collection.

By following these steps and the specific instructions for each note, you should be able to collect all the notes in Vatican City in “Indiana Jones and the Great Circle.”