The birthplace of San Diego -- indeed, of California -- Old Town takes you back to the Mexican California, which existed here until the mid-1800s. Plaza del Pasado is a 1930s-era motel that was turned into a collection of shops and restaurants selling pottery, ceramics, home decor, books, and freshly baked goodies. The complex suffers a tourist invasion daily, but for good reason. Plaza del Pasado occupies a lovely corner of Old Town State Historic Park. It's also a popular spot for California-style Mexican meals and margaritas.
Mission Valley, which starts just north of Presidio Park and heads straight east, is decidedly more modern: Until I-8 was built in the 1950s, it was little more than cow pastures with a couple of dirt roads. Shopping malls, motels, a golf course, condos, car dealerships, and a massive sports stadium fill the expanse today, following the San Diego River upstream to the Mission Basilica San Diego, and just a few miles beyond, an outstanding park with walking trails. Few visitors make it this far, but Mission Trails Regional Park reveals what San Diego looked like before the Spanish arrived.