Kandy Kingdom is a play place in the mall for kids, which sometimes has a Valentine's Day theme. You need to take the Gumdrop Express to get there. It's only appeared in book 6.
This is where Brianna and Chloe wanted to go when they were looking for a birthday present for Brandon. They all rode on the Gumdrop Express. Brianna and Chloe enjoyed the ride, while Zoey and Nikki weren't impressed and didn't want to be recognised, they are embarrassed. This is also the place that Brianna and Oliver, Mrs. Wallabanger's grandson, met.