In each of the 3 world buildings there are doors that are blocked off with wooden planks that prevent you from being able to get inside. There is a portal behind it which clearly makes it somewhere that you can get to, but how? How do you get past doors blocked by wooden planks?
You won’t discover how to do this until you arrive at the building for world C. At the end of the church on the right, you will see an axe mounted to the wall that you can pickup. You can use this axe to break the wooden planks that are blocking the doors and this will let you get inside.