Hamburg Inn No. 2 in Iowa City is a famous campaign stop for visiting presidential candidates leading up to the Iowa Caucus. Candidates seeking the presidential nomination, from Ronald Reagan to Barack Obama to Elizabeth Warren, have visited Hamburg Inn. The restaurant is also known for the iconic coffee-bean caucus, where customers place coffee beans in the mason jar of their candidate of choice. The winner just might reflect who has the best shot at winning the rest of Iowa on caucus night. The diner is known for classic fare like bacon and eggs, coffee, and the indulgent pie shake, a slice of pie blended with soft serve.