During the annual PNC Festival of Lights at the Cincinnati Zoo, some 3 million LED lights illuminate the night. Visitors can meet Mr. and Mrs. Claus, watch a lights show on Swan Lake, drool over a gingerbread village, munch on s'mores or ride the Toyland Express train. 
Photo courtesy of Cincinnati Zoo & Botanical Garden

The 2019 installment of Lights Before Christmas at the Toledo Zoo will feature more than a million holiday lights and some 200 illuminated animal images, as well as an ice slide, photo ops with Santa and an 85-foot Norway spruce tree decorated with 35,000 LED bulbs. Mom and dad can even grab a spiked beverage from the Beer Garden.
Photo courtesy of Toledo Zoo

Some 50 acres at the Cheyenne Mountain Zoo are illuminated with 85 light sculptures during the park's annual Electric Safari. Select animal exhibits remain open during the festivities, and warming fires spread throughout the grounds offer a place to thaw those cold fingers.
Photo courtesy of Cheyenne Mountain Zoo

While enjoying over a million holiday lights, guests of the Saint Louis Zoo during its annual Wild Lights event enjoy campfire s'mores around warming fire pits, holiday carolers and strolling live performances, meet-and-greets with costumed characters and festive holiday crafts. Some animal exhibits, including Penguin & Puffin Coast and the Insectarium remain open during the fun.
Photo courtesy of Saint Louis Zoo

The Living Desert is celebrating its 27th year of WildLights with more than a million lights decorating its pathways and life-size animal lanterns. Visitors can walk through a tunnel of lights, visit with St. Nick, get up close to Santa's reindeer, ride a carousel and participate in holiday arts and crafts.
Photo courtesy of Living Desert Zoo and Gardens

The Indianapolis Zoo is celebrating its 52nd year of Christmas at the Zoo in 2019. The event features Santa’s Village, where guests can meet the merry man himself, decorate cookies with Mrs. Claus and see the reindeer in their barn. Several animal residents will stay up for the illuminated celebration, including seals, sea lions, brown bears, red pandas and tigers.
Photo courtesy of Indianapolis Zoo

Nearly 1 million dazzling lights illuminate Riverbanks Zoo during Lights Before Christmas, one of Columbia's longest running holiday events. Festivities include a Holly Jolly Christmas Parade, nightly visits with Santa, an animated story tree, a Jingle Bell Bonfire and plenty of holiday treats, like s'mores and hot cocoa.
Photo courtesy of Riverbanks Zoo and Garden

LumiNature presented by JP Morgan Chase & Company is new to the Philadelphia Zoo this year. This holiday event features 12 experiences themed around animals in the zoo, like a 21-foot tall snake, hundreds of illuminated penguins, and a 25-foot tree made of flamingo lawn ornaments. Plenty of lights, music and special effects round out the offering.
Photo courtesy of Philadelphia Zoo

Holiday Lights at the California Living Museum (CALM Zoo) is entering its 17th year in 2019 with more than 3 million lights and 250 animated displays across 10 themed lands. More than 400 trees and bushes will be lit, and visitors can pass beneath four tunnels of holiday light. Fresh made apple dumplings and kettle corn are on the menu.
Photo courtesy of California Living Museum

Holiday-lovers of all ages are in for a treat this year at L.A. Zoo Lights with the debut of the World’s Largest Illuminated Pop-Up Storybook. Located in world-famous Griffith Park, L.A. Zoo guests can take a self-guided tour of animal-themed light and sound displays, visit Santa Claus (on select days), shop the local holiday marketplace and warm up over a cup of hot cocoa and festive churros.
Photo courtesy of Jamie Pham / Los Angeles Zoo