Tennessee Aquarium is now celebrating Holidays Under the Peaks through December 29th. Alison Pryor is the media coordinator of the Tennessee Aquarium and describes this as a festive adventure through a fun-filled underwater wonderland. It begins with holiday music and decor in the River Journey lobby. Look for a lighted tree twinkling in sync with the jolly jolts of an Electric Eel.  And in keeping with beloved holiday tradition, The Polar Express 3D returns to the Tennessee Aquarium IMAX 3D Theater.