Melanie Dellas, an Ocean Beach/Point Loma children’s book author, is now co-curating an exhibit at the San Diego History Center in Balboa Park. The exhibit began Dec. 12 and will be open to the public for six months. The exhibit is called “Our City, Our Neighborhoods,” and chronicles San Diego’s diverse neighborhoods rich in history and culture.   The exhibit covers the lengthy inhabitation by the Kumeyaay Indians, the discovery of what is now San Diego by Portuguese explorer Juan Rodriguez Cabrillo in 1542, colonization efforts that began in 1774 and the city’s incorporation in 1850. Today, the city has more than 30 neighborhoods and an estimated population of nearly 1.4 million people. Featured in the exhibit is an overview of eight of these historic neighborhoods:  Southeast San Diego, Barrio Logan, Little Italy, Mission Valley, downtown, Old Town, Point Loma and Hillcrest.   Along the halls of the history center is documentation of the rich history, from the city’s origins in Old Town to the fishermen of Little Italy to downtown’s brothels, opium dens and Wyatt Earp’s gambling halls and saloons.  The San Diego History Center is located at 1649 El Prado, Suite 3. It is open Tuesdays through Sundays from 10 a.m. to 5 p.m. Admission is $6 for adults, $4 for seniors, students and active-duty military and $2 for children ages 6-17. Children under 6 are admitted free. For more information, visit www.sandiegohistory.org.