The Allagash brewery on Industrial Way, north of downtown, runs a free taproom and brewery tour that is one of the best beer experiences in New England. Beyond the classic Allagash White, look for the limited-release lambic-style and spontaneously fermented beers from their famous coolship — only one of a handful of American breweries doing this seriously.
Open most days; tours need to be reserved online. The whole Industrial Way strip has Allagash, Foundation, Battery Steele, and Austin Street within a few hundred metres — an easy afternoon of brewery hopping.