Globe TrotterG 25

There are 11 snowglobes total but this achievement only requires you to collect the 7 found in the base game.

- Goodsprings Cemetery: On the second grave to the west of the Courier's (open) grave, at the northern edge of the cemetery (near the water tower). The grave is the only one in the area with rubble on top; the snow globe can be found among it, in front of the marker.

- Hoover Dam: In the Hoover Dam visitor center, sitting on the welcome desk.

- Mormon Fort: In the Old Mormon Fort in Freeside. Upon entering the fort, go to the western corner and enter the door to the tower. The snow globe is located upstairs on a shelf.

- Mt. Charleston: In Jacobstown lodge. The snow globe is sitting on the reception desk.

- Nellis AFB: Nellis Air Force Base, Nellis Boomer Museum. The snow globe is located on the table to the right, immediately after entering the building.

- Test Site: In the cocktail lounge of the Lucky 38 Casino. The snow globe is on the counter behind the middle cash register with a green lamp and some bar taps next to it (Mr. House must first be spoken to in order to gain access to this area).

- The Strip: In the Vault 21 Hotel, on the nightstand in Sarah's Average-locked room in the northeast corner of Vault 21, next to the room for purchase. Sarah can be pickpocketed for the keys if necessary.

(Credit to the Fallout Fandom wiki: https://fallout.fandom.com/wiki/Snow_globe)

And if you prefer a video walkthrough (credit to Ray Dhimitri):