Escondido is a city located in northern San Diego County, California just north of the city of San Diego. The name means 'hidden' in Spanish - it occupies a shallow valley ringed by rocky hills. Founded in 1888, it is one of the oldest cities in San Diego County. The city has a mild climate, a diverse economy and a growing population of 140,766, making it the fourth largest city in San Diego County in terms of population. Escondido apartments for rent comparison page shows most up to date rent information on Escondido apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.