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

San Marino

In San Marino, 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