At the top of a narrow staircase above Maple Tree Square, the Diamond occupies one of the city's oldest buildings. A bartending school by day, cool hangout and cocktail lounge by night, the venue's official name is the Diamond Preparatory School For All Things Drinks. Standing at the bar, co-owner Josh Pape is like a conductor at the symphony. You can choose among "boozy," "proper," or "delicate" options on the drinks menu. Many are one-of-a-kind concoctions: a Colin's Lawn puts sake and mint together; the Buck Buck Mule is a refreshing mix of gin, sherry, cucumber juice, cilantro, lime juice, and ginger beer; and the Tequila Martinez features tequila, vermouth, Lillet, peach bitters, and an orange twist.