Pokémon Red and Blue/To Lavender Town

Vermilion City

Your next destination is Lavender Town. The fastest way there is via Route 11, to the east of Vermilion City.

Route 11

This Route has paved pathways, lots of tall grass, and no fewer than 10 enemy Trainers. The small cave you see at the beginning of the Route does not lead to Lavender Town, so skip that for now. Towards the east end of the Route you will see an enemy Trainer looking at a bush. If you examine this bush, you will find an Escape Rope.

You will reach a small gatehouse at the east end of the Route. Be sure to go upstairs, as there you will find one of Professor Oak’s assistants. Check the “Owned” number in your Pokédex. If this number is 30 or more, talk to him and he will give you the Itemfinder, which helps pinpoint the locations of hidden items. You will also find an individual willing to trade a Nidorido for a Nidorida. Continue east.

Route 12

Uh oh… what’s this? It seems that a giant Pokémon called Snorlax has fallen asleep in the most inconvenient spot in all of Kanto. You will need a special item to wake him that you do not have. We must turn back, unfortunately. Go back down Route 11, and this time enter the small cave you passed by earlier.

Diglett’s Cave

This small cave is a straight line (well, a diagonal line) connecting Vermilion City to Route 2. It is completely featureless except for the prodigious amount of wild Diglett you will encounter. A Flying-type Pokémon may be your friend here.

Route 2

You will emerge from the cave not far from the north entrance to Viridian Forest. Except, this time, you are located on the other side of those maddening Cut trees you saw when you first came through here. Go due south from the cave entrance. Inside the house, you will find a man who wants an Abra. These common but obnoxious Pokémon flee whenever you try to battle them. If you happen to have a spare one (that hasn’t evolved), you can trade your Abra for Mr. Mime, the only Mr. Mime in the game. Continue south.

Inside the larger building, you will find another of Professor Oak’s aides. If you have a full team of six, plus at least four Pokémon in the PC box (ten or more Pokémon overall), talk to him and he will give you HM 05 (Flash). You will need this soon.

South of there, you will find an HP Up and after that a rare Moon Stone. At this point, since you’re in the neighborhood, let’s do a bit of backtracking. Since you now have Cut, you can destroy the Cut trees to travel around (rather than through) Viridian Forest.

Viridian City

Remember this place? The Gym is still closed. But that’s OK; we’re here for something else. In the southwest corner of the city is a pool of water and a man behind a Cut tree. Destroy this Cut tree and talk to him. He will give you TM 42 (Dream Eater). Now head back north.

Pewter City

Remember the back door to the Pewter City museum? We can now get into that, too. Destroy the Cut tree and enter the building. Inside, one of the researchers will give you an Old Amber. This item works just like the Dome Fossil and the Helix Fossil you saw back in Mt. Moon. If you take this item to a lab in a distant town, you will receive a Pokémon found nowhere else. You now need to return to Cerulean City. You can either go east through Mt. Moon, or back through Diglett’s Cave and north using the underground tunnel.

Cerulean City

Exit east this time. You will find a Cut tree; dispose of it.

Route 9

This Route has a lot of ledges and a lot of enemy Trainers. You will have to take a roundabout path to reach the patch of tall grass you may see just after entering the Route. Due south of the first enemy Trainer, you will find TM 30 (Teleport). If you do wander about in the tall grass on this route, be sure to examine the lone tree at the end of the ledge. You’ll find an Ether hidden there.

Route 10

Now this is interesting. There is only one enemy Trainer on this route, but if you go all the way south you can see a huge building. This is the Power Plant. Sadly, the only way you can reach the Power Plant is via the river that runs down the east end of this Route, but you can’t swim. Remember this place well, though, as a Legendary Pokémon hides within it.

You will find a Super Potion hidden in the cliff face immediately to the east of the cave entrance.

Rock Tunnel

Get ready for another cave. Unlike Mt. Moon, however, you can’t see a thing! It’s pitch black in here. This is the place where the HM for Flash comes in handy. Teach it to a Pokémon and use it to light up the cave. There is little to do in this area except move through it or stay and catch Pokémon. Here is the fastest path to the other side:

Head east, then south at the fork, past the enemy Trainer. (The east path is a dead end.)
Go down the ladder you find at the end.
Go west out of this room; you will find another enemy Trainer here. At the fork, go north; west is a dead end.
Follow the winding trail until you reach another fork in the northeast. Pick either path; they both lead to the same place and both have one enemy Trainer each.
Go up the ladder.
Go south. If you avoid the enemy Trainer here by going west, you will have to fight a different one. Both paths rejoin in an open area. You will find a ladder down the north path.
Go down the ladder.
Go west until you get to the fork; turn south. Go west at the next fork. Then go north and, immediately after that, west again. Go north from there and you will reach another ladder.
Go up the ladder.
Follow the winding path until you reach a fork; go west.
At the south side of this room you will find the exit!

Route 10 (southern part)

You will emerge from the cave right next to an enemy Trainer. Go east instead and search the very conspicuous rock to find a Max Ether. Then go south and you’ll finally reach Lavender Town.

Lavender Town

Finally, a Pokémon Center! Be sure to check out the Poké Mart here, as it sells several new items. This includes the Great Ball (more effective at catching a Pokémon than a regular Poké Ball) and the object called a Revive (use it on a fainted Pokémon and it will un-faint and regain half its health).

In the southeast of the three houses in this town, you will find a man called the Name Rater. This apparent eccentric actually serves a very useful purpose: editing (or adding) the nicknames you give to Pokémon when you catch them.

The house at the center of town is the residence of a kind old man named Fuji. He has mysteriously disappeared.

The large tower to the northeast is Pokémon Tower. You are not intended to explore the tower at this point in the game. If you do, you will run into a rival battle (balanced for a more powerful team than yours is now), and past that you will find that the ghosts inhabiting the tower make progress impossible. You will have to come back later.