Admirers of Greek Revival architecture will find two spectacular examples next door to each other on State Street. The temple-fronted Old Custom House, which was aptly based on the Theseion in Athens (449 BCE), a temple dedicated to the gods of trade and the arts, has over the years housed a bank, a customs house, and now an art museum. The building sits on a podium to raise it above street level, and a marble staircase leads to its oversized double doors. Six Doric columns support a wide entablature and pediment of white Vermont marble. Architectural historian Talbot Hamlin in Greek Revival Architecture in America (1944) describes William Kelly's design as vital, sensitive, and archaeologically correct.

The L-shaped former Cashier's House just south housed the president of the bank. It is a severe and handsome Greek Revival town house, three bays wide with a side hall and windows graduating from the largest on the first story to the smallest on the third. The paneled door is outlined with pilasters, a rectangular transom, and a tall entablature echoed in the cornice that concludes the building's facade. Though made of brick, the building is stuccoed and scored to emulate stone. The interior includes elaborate Egyptian Revival decorative motifs in the public rooms. Today, the building is operated as a historic house museum by the Erie County Historical Society.