Simplify the following text for a Grade 13 native English-speaking person.
Original: The municipality of Rosignano Marittimo contains the frazioni ( subdivisions , mainly villages and hamlets ) Castiglioncello , Rosignano Solvay , Vada , Castelnuovo della Misericordia , Gabbro , and Nibbiaia .
Simplified: The comune of Rosignano Marittimo contains the frazioni of : Castiglioncello , Rosignano Solvay , Vada , Castelnuovo della Misericordia , Gabbro , and Nibbiaia .