Question: What specifically do you mean by "Baltimore native?" I feel like this could sort of be all over the place, was she born and raised in the city, move here after college, or what?

So the aquarium is awesome. As such it is probably the single most popular (non food non sports) attraction in the city. If she dates a lot there's a decent chance she's already been on a date to the aquarium. It could definitely be an eye-rolly suggestion. But then on the other hand there are probably girls who have lived in Baltimore their whole lives and never gone, possibly due to economic reasons, and they might really want to go.

With this, honestly, I'd just ask. It's not like you're both on the same footing and you're being wack not picking something, you're entering her area of expertise. Why not just say, "I'm not familiar with the city, I'm more than happy to pick a place but am worried it might seem like a lame touristy choice. Do you know any where cool to grab a drink or coffee?"