The Sodom Schoolhouse was listed on the National Register in 1974 (number 74001799) partly because the octagonal shape is very unique for the region. The town (which no longer exists) and schoolhouse were named in honor of local tavern owner and town official, Lot Carson (per the biblical passage). He donated much of the building materials for the school.
It hasn’t been in use since 1915, but it was restored by the WPA starting in 1935, and completed in 1961 by the Junior Historians Club at Milton High School. In 1968, it became the property of the Pennsylvania Historical and Museum Commission.
There are local legends that claim it was built in the 1770’s as a fort, or from 1812-1817 when construction was interrupted by the War of 1812, but the generally accepted date is 1835 when a survey was made for school use (much less exciting). It was also used as a Methodist church until 1858.
Sources:
National Register Application PDF
Society of Architectural Historians, Archipedia, Sodom Schoolhouse