Uh oh! A new Poptropica update has completely removed all the old islands from the map. There is no way to manipulate the game into redisplaying them, but you can use these links to load the old island you desire.

Early Poptropica
Shark Tooth
Super Power
Spy
Nabooti
Big Nate
Astro-Knights
Counterfeit
Reality TV
Skullduggery
Steamworks
Great Pumpkin
Cryptids
Wild West
Wimpy Wonderland
Red Dragon
Shrink Ray
Mystery Train
Game Show
Ghost Story
S.O.S.
Vampire's Curse
Twisted Thicket
Charlie and the Chocolate Factory
Wimpy Boardwalk
Lunar Colony
Super Villain
Zomberry
Night Watch
Back Lot
Legendary Swords

All other islands are accessible through the travel map. If you want the old islands added back to the map, tell the developers! You can contact them by posting comments on the Creator's Blog and messaging the official Poptropica social media accounts.
Tweet @Poptropica - Facebook Page - Creator's Blog