Philadelphia knows how to do the holidays right. From its historic streets dressed in twinkling lights to festive pop-ups and parades, the city hums with seasonal cheer. But if you're looking for something unexpected — something that'll wow your kids and have even the grown-ups grinning — head across the Delaware River to Adventure Aquarium.
Every winter, the aquarium transforms into a holiday wonderland with its Christmas Underwater celebration, complete with glowing jellyfish, a scuba-diving Santa, indoor snow, and the world's tallest underwater Christmas tree. It's festive, it's fishy, and it's a must-see if you're in the Philadelphia area during the holidays.
In this article, you'll get the full scoop on what makes this event so special, which highlights to catch, how to plan your visit, and how to pair it with other family-friendly attractions using CityPASS® tickets.
What Makes the Aquarium's Christmas Celebration Stand Out
Christmas Underwater isn't your typical holiday lights show. There are glowing installations and cheery decorations, but what sets this event apart is its deep-sea setting. You're not walking through a forest of lights or skating beneath skyscrapers — you're exploring the deep sea with a festive twist.
The aquarium decks out multiple zones in holiday cheer, including the massive Shark Realm exhibit where you'll find the towering underwater tree. Themed music sets the tone, and the marine life seems to play along with the merriment. Add in Scuba Santa — yes, he swims with the fish — and you've got a holiday experience that feels more like an adventure than a standard outing.
Signature Experiences at Christmas Underwater
If you're building your seasonal itinerary around things to do in Philadelphia in the winter, this limited-time event belongs on your list. It only runs from late November to just before Christmas, so timing your visit right means catching the aquarium at its most magical.
Adventure Aquarium's Christmas Underwater event is filled with immersive, can't-miss features. Here are the stars of the show.
Scuba Santa
You read that right. Scuba Santa trades in his sleigh for fins and dives into the 760,000-gallon Ocean Realm exhibit, swimming among sea turtles, sharks, and stingrays. Guests can interact with him and snap selfies underwater.
World's Tallest Underwater Christmas Tree
Within the 550,000-gallon Shark Realm exhibit, you'll find the "world's tallest underwater Christmas tree," nestled among one of the largest shark collections in the Northeast. It's a show-stopper photo op: shimmering lights, oversized ornaments, and aquatic animals drifting past.
Indoor Snow "Snow-tunda"
Every hour on the hour, guests are treated to indoor snow in the Rotunda. Yes — it snows inside the building! It's a recurring experience, so if you miss it once, you've got another chance in just 60 minutes. That reliable schedule makes it easy to plan your walk-throughs or photo ops around the snowfall.
Holiday-Themed Animal Exhibits & Décor
From a brand-new rainbow tree in Kaleidoscope Cove to thousands of glowing, festive decorations surrounded by aquatic life, the entire space gets a makeover. The exhibits are filled with twinkling lights and cheerful decorations, transforming the space into an immersive winter wonderland. And keep an eye out for Gill, the aquarium's playful shark mascot, who makes special appearances dressed in his holiday best. He's a hit with the kids and a favorite for festive selfies.
Tips for Visiting With Kids or Groups
Planning a holiday outing with younger kids or a larger crew? Christmas Underwater makes it easier.
- Since most of the exhibits are indoors, unpredictable winter weather won't ruin your plans. You get holiday spirit plus warm spaces filled with fish (think tropical vacation vibes).
- The space is stroller-friendly with plenty of rest areas — a smart choice for families.
- For fewer crowds, aim for weekday visits or early afternoon when possible.
- Bring your camera (or phone) and make time for the special photo spots: the underwater tree, Scuba Santa, indoor snow, and the rainbow tree in Kaleidoscope Cove.
- Don't forget the scavenger hunt — it adds a bit of playful structure if you're visiting with a group and helps keep kids engaged.
- Since some of the extras (like the meet & greet or scavenger hunt) may carry add-ons, check ahead for any updates when you plan your visit.
If you're visiting from out of town, it's worth brushing up on a few Philadelphia travel tips to make the most of your holiday itinerary, from navigating neighborhoods to getting around the city smoothly.
Other Holiday Attractions to Pair With
One of the best parts of visiting Philadelphia in the winter is that there's no shortage of family-friendly indoor attractions included with CityPASS® tickets.
After your underwater holiday adventure, warm up with a visit to the Franklin Institute, one of Philly's most engaging and kid-friendly museums. Kids can climb through a giant heart, explore space in the planetarium, or experiment with physics and engineering in interactive exhibits. It's a perfect way to keep the energy high while staying indoors during the colder months.
For art lovers, the Barnes Foundation offers a warm escape into one of the world's most impressive collections of Impressionist, Post-Impressionist, and early Modern paintings. Strolling through its galleries feels especially cozy in winter, and the museum often features seasonal programs and festive décor that make December visits even more memorable.
If your crew is curious about the natural world, head to the Academy of Natural Sciences of Drexel University, where dinosaurs, dioramas, and hands-on exhibits bring science to life. Kids can dig for fossils, marvel at towering skeletons, and explore ecosystems from around the globe—all without braving the cold. It's a perfect mix of education and adventure during the holiday season.
There's no shortage of seasonal fun to keep your crew entertained. From classic displays to indoor escapes, the city delivers on holiday cheer. And for those drawn to history, many Philadelphia attractions take on extra charm when dressed up for the season.
Plan Your Visit with CityPASS® Tickets
Holiday outings can add up fast—especially when you're traveling with family or visiting multiple spots. With Philadelphia CityPASS® tickets, you get prepaid admission to top Philadelphia attractions like Adventure Aquarium while enjoying savings. It removes the stress of picking and choosing, so you can check off a bunch of fun stops all in one go.