You Do Need power plug adapter while traveling from Antigua and Barbuda to San Marino.

Here is Why You Need An Adapter

The outlet and plug type used in San Marino are C, F and L and in Antigua and Barbuda are A and B. This is how they look like.

Antigua and Barbuda

In Antigua and Barbuda, outlets of type A and B are in use.

Type A

Type B

San Marino

In San Marino, outlets of type C, F and L are in use.

Type C

Type F

Type L