The city the series is set in is located in the Pacific Northwest
Geographical clues point to it, such as the city having a streetcar system and the architecture resembles San Francisco.- Also, in "Driedel Dilemma", when the pups fly to Florida, in a shot of the map it shows the destination as Oregon, hinting to where it might be located.
The cave seen in "The Legend of Captain Wunderbark" is actually an abandoned theme park
The place is in a very good condition with almost no signs of decay. Even the machinery is still working (although, maybe, not the intended way). That means it can't have been abandoned very long ago. And it actually makes more sense for it to be a tourist attraction dedicated to the old legend rather than an actual hideout:- There is a water slide (which apparently uses some natural water source), which is sort of odd for a hidden base, but makes perfect sense in a theme park.
- The sign above the entrance is way too large and obvious - if it was a real lair, making such thing would immediately give out its location; also, it would've been found already.
- The booby trap above the table can't really catch anyone, but it may have served some different purpose as a part of some quest room or a live show.
- The ship sank when the characters tried to sail it - apparently, it wasn't intended for such use.
- Finally, there is the fact that no one has still found Wunderbark's hideout, but at the same time such a large structure is very unlikely to stay undiscovered in a place like this beach. This means that people likely know about the place the pups found. They just don't mention it in the context of the episode, since it obviously cannot confirm the veracity of the old legend.
