Original sentence: Calico is a registered California historic monument, and is one of a number of ghost towns in California (other examples are Drawbridge, California and Bodie).It is open daily, and requires an entrance fee  During the tours, one may see silver ore so rich that there are gray spots of silver in the rock
Edited sentence: Calico is a registered California historic monument, and is one of two authentic ghost towns in California (the other is Bodie).During the tours, one may see silver ore so rich that there are gray spots of silver in the rock.It is open daily, and requires an entrance fee