Grandmum's Cottage is in the Poconos region in Pennsylvania (The Doom Funnel Rescue reveals the zip code 725-5068.) The cottage seems to be located close by a lake in the backyard.
History
The house was built by Granddad after he and Grandmum's honeymoon, and it still stands to this very day.
Jason and Michelle are sent to spend the summer there while their parents are away.
Episode appearances
The cottage appeared in every episode of 3-2-1 Penguins!
Gallery
Trivia
A picture of the cottage appeared in An Easter Carol.