Open continuously since 1826, Union Oyster House is the oldest restaurant in the United States. The brick building on Union Street is older still: it housed the Capen family in the 1740s, served as a clothing store and a pre-Revolutionary printing office (the Massachusetts Spy was published from the upstairs in the 1770s), and finally became an oyster bar in the mid-1820s.
The food is straightforward New England — clam chowder, oyster stew, scrod, lobster — and the prices reflect both the central location and the tourist appeal. The chowder is good and well peppered; the oysters, from local beds, are reliably fresh. JFK had a favourite booth upstairs, marked with a plaque.
The semicircular oyster bar by the front door is the original, and you can still sit there and watch oysters being shucked. Worth the visit for the place rather than the cuisine.