This charming challenge, inspired by popular Christmas carols, is the perfect way to prepare for Santa’s arrival. The fun-filled treasure hunt gives you the chance to take over the National Portrait Gallery after hours. Once you’ve solved the clues and found the treasure, relax with a festive drink while you await the prize giving. It ain't Xmas till you've completed The 12 Days of Christmas Late Night Treasure Hunt. Over 18s only. Teams must consist of 2 or 4 players.