Formerly a fireman's bar, this classic Irish pub in Lincoln Park has had the same owner since 1974 (it opened for business in 1946). The etched-glass doors, tin ceilings, exquisite antique bar, green velour curtains and old sepia prints of Chicago on the walls give River Shannon its authentic feel. A jukebox, 11 types of Irish whiskey and 38 kinds of beer keep the crown hopping. The place is especially popular with the over-30 crowd and with late-nighters. ''It's a great conversation bar,'' says one regular seated at the bar, laughing. ''There's nothing else to do here.''