The crown jewel of Riverside: a sprawling Mission Revival and Spanish Colonial hotel built over five decades (1876–1932), with towers, catacombs, a chapel, stained glass, bells, and antique collections around every corner. Even if you are not staying the night, the public areas are open for walk-throughs at no charge. The architecture alone is worth the trip — architects and decorators layered styles and eras into something that feels genuinely singular. Every November through January, the annual Festival of Lights transforms the exterior into one of Southern California's most spectacular Christmas light displays.