You Do Need power plug adapter while traveling from Costa Rica to Vatican City.

Here is Why You Need An Adapter

The outlet and plug type used in Vatican City are C, F and L 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

Vatican City

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

Type C

Type F

Type L