Secret sub-neighborhood
A Secret sub-neighborhood is a special type of sub-neighborhood in The Sims 2. First appearing in The Sims 2: Pets, this type of sub-neighborhood adds many new things to an already existing neighborhood, such as new families in the family bin, new townies, and secret lots. A secret sub-neighborhood can only be visited, not lived in, and its lots can not be edited.
Pets
In The Sims 2: Pets, the secret sub-neighborhood is called Pets. It adds new Pet townies that are able to go into the main neighborhood and any other non-college sub-neighborhoods. It also adds the Roseland family and the Crittur family, both of which can be placed in the main neighborhood or any non-college sub-neighborhoods.
Weather
In The Sims 2: Seasons, the secret sub-neighborhood is called Weather. It adds the Garden Club Sims that are able to visit any lot in the main neighborhood and any other non-college sub-neighborhoods. The families it adds are the Ottomas family and the Ramaswami family, which can be placed into the base neighborhood or any non-college sub-neighborhoods.
Exotic Destinations
In The Sims 2: Bon Voyage, the secret sub-neighborhood is called Exotic Destinations. It adds the "tourist" townies that appear at the vacation destinations. The family it includes is the Traveller family.
Hobbies
In The Sims 2: Freetime, the secret sub-neighborhood is called Hobbies. It includes many new secret lots, called Hobby lots, the Hobby instructors, and two new families, the Picaso family and the Cooke family. Unlike earlier secret sub-neighborhoods, lots in Hobbies can be visited. If a Sim has at least level 5 enthusiasm in a hobby, Hobbies will appear as one of the available destinations when he or she travels to a community lot.
Magic
In The Sims 2: Apartment Life, the secret sub-neighborhood is called Magic. It adds two new lots, the Palace of Neverending Light and the Fortress of Eternal Darkness, new Witch Sims, many social group townies, and three new families, the Gavigan family, the Goodie family, and the Newson family.