Here are a few treasures on Horse Isle.
Step on the crossroads sign next to the General Store in Earton and dig
Go to the northern moat on Ice Isle. Step to the west (left) side of the moat and dig.
Go to the drinking fountain on Hoof Isle. Step below the fountain and dig
Go to Jungle Isle and digging around the jungle statues you can find different treasures.
Go to Hotzplotz Isle. King Phil has a quest for you go to the right of one of the palm trees and
take one step up and dig. Tell King Phil about the treasure. Don't ask if if he wants to buy it
back for 20,000 because he will send you to prison isle.