Let XJC consider some parts of the schema as String

Some parts of the schema I don't need JAXB-objects and I want to consider those parts as a String. Basicly it is about GML

Example:

<xs1:City>
  <xs1:Surface>
    <gml:Surface>......
    </gml:Surface>
  <xs1:Surface>
</xs1:City>

What I need is that XJC generate a JAXB-class with a property named Surface being a String.
so:
public class City {
....
  protected String Surface;
...
}