You Do Need power plug adapter while traveling from Costa Rica to Western Sahara.

Here is Why You Need An Adapter

The outlet and plug type used in Western Sahara are C and E and in Costa Rica are A and B. This is how they look like.

Costa Rica

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

Type A

Type B

Western Sahara

In Western Sahara, outlets of type C and E are in use.

Type C

Type E