After 100 years and multiple changes, the Sink remains one of Boulder’s most quirky and popular taverns, as much for the good deals on booze as for the famous Sink Burger (which first appeared on the menu in the 1950s) and “ugly crust” pizza. History is scrawled across the ceiling and walls in the form of customer autographs and Beat-era paintings. Barack Obama stopped in during his presidency, and Robert Redford was a janitor here for a year before he ever hit the silver screen. Over the decades, the Sink has helped shape Boulder’s image into what it is today.