Scrolling the View and Movement
You can scroll the view of the current area by clicking anywhere in the world and dragging the mouse.
There is a thin bridge of land to an island that you can see if you scroll to the right. Move onto the island by first scrolling the view and then left clicking over an island tile where the mouse turns into the boots icon.
Note that you may find this easier if you first close any open windows, such as the Inventory window or the Container window from the chest you opened.