You Do Need power plug adapter while traveling from Vatican City 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 Vatican City are C, F and L. This is how they look like.

Vatican City

In Vatican City, outlets of type C, F and L are in use.

Type C

Type F

Type L

Costa Rica

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

Type A

Type B