You will get the Go-Goggles in Lavaridge Town immediately after beating the fourth Gym Leader Flannery. This is part of the main storyline, which makes the Go-Goggles an unmissable key item.
With the Go-Goggles, you will be able to cross through the sandstorm in Route 111’s desert area.
Obtaining the Go-Goggles (Step-by-Step)
In order to get the Go-Goggles, you need to first obtain the Heat Badge in Lavaridge. The Gym has a very simple puzzle that requires you to step on trapdoors and platforms.
Lavaridge Gym Quick Puzzle Guide
There are seven trainers in the Gym, and six of them are avoidable.
If you choose to fight them, be prepared to take on Fire, Fighting, Psychic, Poison and Normal types. Their levels range from 24 to 26.
Step 1: From the Gym’s entrance, head up and step on the trapdoor.
Step 2: From the current position, step on the right-side platform.
Step 3: Move up from your current position and step on the trapdoor.
You can avoid fighting the Kindler trainer ahead. Stay close to the wall and wait for him to turn around.
Step 4: From your current position, head over to the left-side of the room.
There is a Ninja Boy trainer hiding underwater and off-screen. In order to avoid him, stick to the wall on the upper side.
Step 5: Step on the leftmost platform.
Step 6: Head up from your current position and step on the uppermost trapdoor.
You can also avoid fighting the two trainers on this floor. Wait for the Kindler to pass by and head over to the right-side of the room. Stay close to the wall to avoid the Battle Girl.
Step 7: From your current position, head over to the right-side of the room.
There is another Ninja Boy hiding off-screen. You can avoid him by staying close to the upper-side wall.
Step 8: Step on the rightmost platform.
Step 9: Head to the bottom-side of the room and step on the last trapdoor.
There is an Ace Trainer hiding off-screen. To avoid him, move to the upper wall as soon as you step off the trapdoor. While heading to the bottom of the room, stay close to the wall on either side and wait for him to turn around.
Step 10: From your current position, step on the platform to the left.
Note: You will battle Kindler Andy before reaching the platform. This is the only unavoidable fight in the Gym. He only has one Pokémon, a level 25 Numel, making it an easy battle.
Step 11: Head up the stairs to challenge Gym Leader Flannery.
Her team consists of a Slugma and a Numel, both level 26, and a level 28 Torkoal. Using a Water-type Pokémon with high Special Attack is the best option for this fight.
Step 12: Defeat Flannery to win the Heat Badge.
Step 13: Head down and exit the Gym by jumping over the ledges. Watch out for the trapdoors.
Getting your Go-Goggles
As soon as you step outside the Lavaridge Gym after defeating Flannery, your rival will show up and give you the Go-Goggles.
With the Go-Goggles equipped, you will be able to cross the sandstorm and get the Root Fossil or the Claw Fossil.
And much later in the game you will also gain access to the Desert Ruins, where you will be able to catch Regirock.