They are the wine bottles in different locations of Bhujerba, obtain and sell them to the appointed NPCs, each Bhujerban Madhu can be sold for 1000 gil. All together are 14 Madhus, that's mean you could have 14000 gil here.

You can start to collecting them after Tomb Of Raithwall event. Here are the Bhujerba Madhus location, you could get them randomly,

1. Inside Airship Terminal, from the entrance head to right area. It's on the traveller's bag.

2. Inside Armor Shop, in the third left carbinet.

3. Inside Weapon Shop, turn right from the first stairs. It's in the corner.

4. Inside Magic Shop, turn left from the first stairs, It's on the carbinet.

5. Outside Magic Shop, go South from there. It's behind the man with a boy.

6. Inside Skill Shop, just beside the second stairs.

7. Inside Gambit Shop, in the bookcase at left side.

8. Outside Gambit Shop, it's on the crate at right side.

9. West Item Shop, find the left side of it. It's on the crate along with a moogle.

10. Middle section inside the resident's house, it's in the right corner.

11. Middle section, the right end crates outside the resident's house, it's on the crate.

12. Inside the Inn, on the middle table.

13. In front of Lhusu Mines, find it at bottom of the water engine pool.

14. South-East section, behind the blue seeq.
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Of cause, you do have to find the buyers to buy them. Here are the buyers location, yoou can sell more than one to each of the buyers, just exit and re-enter the area after selling it.

1. Inside Airship Terminal, from the entrance head to right area.
The man with blue hat.

2. Inside Armor Shop.
The old lady in front of the counter.

3. Inside Weapon Shop.
Female resident in green.

4. Inside Magic Shop.
The Informer at the left corner.

5. Outside Magic Shop.
The man opposite of the shop.

6. Inside Skill Shop.
The moogle in the middle.

7. Inside Gambit Shop.
The seeq staff by the left front corner.

8. Outside Gambit Shop, head to South.
The gray bangaa on the slope.

9. West section.
Female resident at Western most.

10. Middle section inside the resident's house.
Female inside, who's also the client of Antlion Mob Hunt (rank A).

11. Inside the Inn.
The seeq near the window.

12. Outside the Inn.
The man in front of the Inn.

13. In front of Lhusu Mines section.
The Miners beside Item Shop.

14. South-East section, go down to left area.
Female resident looking to ouside.