Pokémon Red and Blue/Cinnabar Island

'One of the Pokémon research centers on Cinnabar Island has been destroyed. A genetically engineered Pokémon broke free of its cage and escaped, demolishing the lab in the process. Luckily for you, the cloning facility is safe and sound. You'd better be careful as you walk the creature's back reail—be sure to read any literature you might find to learn about this doomed experiment.'

Pokémon Lab
Don't let its small size trick you—there are loads of opportunities in Cinnabar Island.

The traders in the Lab won't give you the greatest deals (in Yellow: for,  for , and  for ; in Red/Blue:  for ,  for ,  for ), but the scientist in the next room will make a better offer: TM 35 (Metronome) for free. This fun but unreliable skill dishes out various special attacks at random.

The scientist in the last room will take your fossils and turn them into Pokémon. Give your fossil and the Old Amber to the scientists here. He claims the process will take a while, but if you simply leave the building and come right back he'll be finished. You will receive living examples of prehistoric Pokémon.

An island paradise?
Not quite. The gym is locked up tight. The key to the front door is in a nearby building. Once you've found a way in it's possible to avoid confrontation, but it'd be wise to fight all of Blaine's underlings to gain experience. So where to look? Rumors say that the genetically engineered Pokémon known as was created in a facility on the island. Why not have a look in the Mansion?