Three will be put in every one of the historical center's Animal Crossing Items three displays.
(fish, bug, and fossil), making for a sum of nine stamps. Gathering three in each show grants the player with an uncommon plaque of each sort.
Your Stamp Rally card will have pieces of information about the particular shows inside the gallery you'll have to visit. Basically head to the areas it instructs you to get your stamp. In my first run, I needed to get stamps from the Coral Reef, The Pond, and Serenity Tank. Those last two were near one another, however the Coral Reef was off in a side of the exhibition hall that Buy Animal Crossing Items I didn't visit frequently.