The largest building at the Corner of the Past site is known as the Koessl Barn, which once dominated the 90-acre Koessl Farm and Homestead located on Highway 57 just east of where Hwy 57 and Hwy 42 meet south of downtown Sister Bay.

Built in 1887, the barn, approximately 103’ x 45’, was built in the “Post and Beam” style of construction. In building construction, this is a system in which two upright members, the posts, hold up a third member, the beam, laid horizontally across their top surfaces. The barn siding was constructed of Hemlock wood harvested in and hauled from the Carlsville area. The boards were one foot wide by one inch thick by 18 feet long. No nails were used in its construction. Instead, beams were fitted together in tongue and groove-style using handcrafted wooden pegs. The historic Koessl barn was once used as a livery stable for the stagecoach horses coming through Sister Bay.