You Do Need power plug adapter while traveling from Åland Islands to Costa Rica.

Here is Why You Need An Adapter

The outlet and plug type used in Costa Rica are A and B and in Åland Islands are C and F. This is how they look like.

Åland Islands

In Åland Islands, outlets of type C and F are in use.

Type C

Type F

Costa Rica

In Costa Rica, outlets of type A and B are in use.

Type A

Type B