Every December, more than 400,000 revelers flock to Zilker Park, in Austin, to admire some two million lights during the Trail of Lights holiday festival. Folks online always make the same wry observation: The real Trail of Lights—so the joke goes—is the long line of taillights from all the cars idling in the event’s infamous traffic jams. (We suggest taking the shuttle bus for a more relaxing experience.) For those willing to brave the crowds, Texas boasts lots of big, splashy holiday events—not just the Trail of Lights, but also San Antonio’s floating parade along the River Walk, Sugar Land’s Holiday Lights, and Grapevine’s forty-day Christmas extravaganza, whose more than 1,400 (yes, you read that right) events and attractions include a drone show and a…