Rialto is an Inland Empire city in San Bernardino County that makes a solid multi-week base—more affordable and low-key than coastal hubs, with easy freeway access, a growing local dining and retail scene, and quick routes to outdoor recreation in the nearby San Bernardino Mountains.
For bigger-city options, San Bernardino and Riverside (both roughly 20–40 minutes away) offer museums, theaters, diverse dining and larger shopping districts, and Los Angeles is doable for occasional big-city weekends.