I will admit that I haven't been to Baltimore in 17 years, but I always considered this to be the crown jewel of the Inner Harbor redevelopment. It's the National Aquarium-- visually interesting and fascinating inside and out.
A check the other morning showed it cost $40 to get in, and that's a bargain.
This is a photo for the late 80's.
By the way, the debate over conditions in Baltimore was wiped off the front pages with amazing speed.