Downtown San Diego, also known as Centre City, is the city center of San Diego with a population of more than 37,000. Downtown San Diego contains nine different districts and over 4,000 businesses. It’s the hub spot of San Diego providing residents with tons of housing options, restaurants, shopping, workplaces and things to do. Find out what makes Downtown San Diego so unique to San Diego County and an ideal place to explore or live in. History of Downtown San Diego Downtown