If you're in the inner Harbor, the only brewery I know of that is down there is DuClaw. Not bad, but not great beers.
You're better off hitting Max's on Broadway which has a huge selection of beers and a good 20+ taps in the downstairs bar.
Here's a site with all the local breweries and addresses. Brewer's Art is a good place for Belgians, both brewed locally and imported.