Located right in the center of the Newtrogic High Zone and styled as an amusement park, World Entrance is the nerve center of Dr. Robotnik’s entire island base. It is here that the transition to all stages of the island and the Combi Catchers with captured heroes are located. In addition, the local mechanisms are specially designed to enhance Metal Sonic in the event of a battle in the center of World Entrance.

Wiki Zones
Isolated Island

The training area and Newtrogic High Zone’s safest place, Isolated Island refers to the coast of Dr. Robotnik’s captured island, which is free of robots and traps, but which contains a Combi Catcher with Espio captured in it. It is from here that Knuckles begins the liberation of the island and frees Espio.