“Naples 2015 Conference in Group Theory and Applications” has no special agreements with any hotel. There is a wide variety of hotels in the city. The conference location is in the hystorical center of Naples and it can be easily reached by public transportation, so that you can comfortably choose an accommodation in other areas of the city, too.
Moreover, it could be logistically convenient a hotel near the Central Railway Station, since the conference location is within walking distance of it. Anyway, consider that some incovenience could derive from the crowding of the area, as it is usual nearby the central station of big cities.
Following the links below, you can find a list of hotels.

Link 1

Link 2