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Can I get opinions on this for a Dronia map?
There are places where you can slip between buildings and enter a back alley grotto (not mapped yet). I don't know what will be in them - trainers, hidden items, wild Pokémon - but they're extra places to explore.
I was originally going to make the harbour area a pocket dimension, letting it be larger with more stuff in it, but I ran out of time. I've settled for what's here, which implies there's more to it but you can't access it (yet?).