Is there free parking at the baltimore aquarium if yes were?

No.





You can pay high fees close, or you can park a few blocks North East around the post office area, (north of Fayette Street) where meters are cheap.





You might also find cheap meters, or if you're lucky a free spot about a half mile east in the Little Italy/Fells Point area.





The above is assuming you go during the day. If you go on Sundays, or after 6pm, there should be some free parking within a few blocks.