Emerald Mound and Village Site

Lebanon Township is located in St. Clair County, Illinois. As of the 2010 census, its population was 4,538 and it contained 2,005 housing units.

Mermaid House Hotel, located on East St. Louis Street in Lebanon, Illinois, was built in 1830 by the retired New England sea captain Lyman Adams. He named it for the mermaids he reported seeing at sea. The Mermaid House was visited by Charles Dickens in 1842 and received a mention in his book American Notes. The public-house was so very clean and good a one, that the managers of the jaunt resolved to return to it and put up there for the night, if possible. This course decided on, and the horses being well refreshed, we again pushed forward, and came upon the Prairie at sunset. Returning to Lebanon that night, we lay at the little inn at which we had halted in the afternoon. In point of cleanliness and comfort it would have suffered by no comparison with any English alehouse, of a homely kind, in England. The Mermaid House was added to the National Register of Historic Places on December 4, 1975.

Lebanon is a city in St. Clair County, Illinois, United States. The population was 4,418 at the 2010 census and had decreased to an estimated 4,256 as of 2018. Like many other places in "Little Egypt" or Southern Illinois, Lebanon was named after the Eastern Mediterranean country of the same name. It is a part of the Metro-East region of the Greater St. Louis metropolitan area. Lebanon is home to McKendree University, the oldest college in Illinois.

The Lebanon Historic District is a historic district composed of the areas of Lebanon, Illinois, developed prior to 1900. The district includes five distinct areas of Lebanon: the city's main commercial district, the neighborhood around McKendree University, two residential districts, and an archaeological site at the city limits. Development in Lebanon began in the 1820s, and McKendree University was founded in 1828. The oldest building from this period, the Mermaid House Hotel, is a Federal structure dating to 1830. The city received an influx of German immigrants from the 1830s onward, which affected the city's development. In the 1850s and 1860s, a railroad opened in the city and several local industries developed; however, the city retained the character of a small college town and never developed into an industrial or trade center.The historic district was added to the National Register of Historic Places on October 4, 1978.

McKendree University (McK), formerly McKendree College, is a private university in Lebanon, Illinois. Founded in 1828 as the Lebanon Seminary, it is the oldest college or university in Illinois. The school was renamed McKendree University beginning in the 2007–08 academic year. McKendree enrolls approximately 1,960 students representing 25 countries and 29 states. In the undergraduate program, on average there are 51% females and 49% males. The institution remains affiliated with the United Methodist Church.

Lebanon High School is the public high school of Lebanon Community Unit School District 9 in Lebanon, Illinois.

Summerfield is a village in St. Clair County, Illinois, United States. The population was 451 at the 2010 census.

St. Jacob Township is located in Madison County, Illinois, in the United States. As of the 2010 census, its population was 2,578 and it contained 981 housing units.

O'Fallon Township is located in St. Clair County, Illinois. As of the 2010 census, its population was 26,053 and it contained 10,338 housing units.

MidAmerica St. Louis Airport station is an under construction St. Louis MetroLink station in Mascoutah, Illinois, adjacent to MidAmerica St. Louis Airport, after which the station is named. When opened, this station will be the eastern terminus of the MetroLink system. It is scheduled to open in spring 2025 as part of a 5.2-mile (8.4 km) expansion of the Red Line from Shiloh–Scott station.

St. Jacob or Saint Jacob is a village in Madison County, Illinois, United States. The population was 1,358 at the 2020 census, up from 1,098 in 2010.

MidAmerica St. Louis Airport (IATA: BLV, ICAO: KBLV, FAA LID: BLV) is a public use airport next to Scott Air Force Base. It is located 18 nautical miles (33 km; 21 mi) east of downtown St. Louis and 14 nmi (26 km; 16 mi) east of the central business district of Belleville in St. Clair County, Illinois, United States. Opened in 1997, MidAmerica is the secondary domestic passenger airport for the Greater St. Louis metropolitan area, after the larger St. Louis Lambert International Airport. It is a joint-use airport and is currently served by one airline, Allegiant Air. The airport had 152,278 passenger enplanements in 2018 (302,000 total passengers), according to the Federal Aviation Administration. It was included in the National Plan of Integrated Airport Systems for 2017–21, which categorized it as a primary commercial service airport because it surpassed 10,000 annual enplanements. It is the fifth-busiest of the 12 commercial airports In Illinois.