Perhaps the best known area of downtown San Diego [1], the Gaslamp Quarter (Fourth, Fifth, and Sixth Sts. and Broadway) exudes atmosphere, whether you visit during the day or night. Of course, the Gaslamp Quarter has exuded atmosphere since its earliest inception in the 19th century. The Fifth Street Pier led sailors right to the area, where saloons and brothels flourished.
Ida Bailey—a famous lady of the evening—moved in and cemented the area (then called Stingaree) as a red-light district. After decades of thriving debauchery, a police raid in 1912 heralded the end of the Gaslamp Quarter’s popularity.
Throughout the first two-thirds of the 1900s, the area decayed, becoming a low-rent district filled with porn theaters and liquor stores. In the mid-1970s, the Gaslamp Quarter Association came to be, and the renewal of this downtown area began.
Today, the Gaslamp Quarter bustles with foot traffic, both locals and tourists. People crowd into the popular and sometimes quirky restaurants, dance like mad at the many bars and clubs, and spend their cash in the shops and boutiques. (But only tourists insist on taking photos under the Gaslamp Quarter sign.) Ghosts reputedly haunt several buildings here; check into a ghost tour or explore on your own to try to see or feel a spook.
In general, the Gaslamp Quarter is quite safe, though you will see a scattering of homeless people wandering and sometimes sleeping on the sidewalks. In the evenings, the gaslamp-shaped streetlights illuminate the sidewalks and the historic architecture of some of the structures, especially along Fifth Street.
Links:
[1] http://www.moon.com/destinations/california/san-diego