Grand Lake St. Marys Lighthouse

Grand Lake St. Marys State Park is a public recreation area located on 13,500-acre (5,500 ha) Grand Lake in Mercer and Auglaize counties, Ohio. Grand Lake is the largest inland lake in Ohio in terms of area, but is shallow, with an average depth of only 5–7 feet (1.5–2.1 m). The state park is open for year-round recreation, including boating, fishing, swimming and hunting. The park consists of the lake and park facilities scattered all around the shore intermingled with private property and a facility operated by Wright State University. It is west of St. Marys, and southeast of Celina, 23 miles (37 km) southwest of Lima in the northwestern part of the state.

Villa Nova is an unincorporated community in Saint Marys Township, Auglaize County, Ohio, United States. It is located just west of Saint Marys on the northeastern corner of Grand Lake at the intersection of Ohio State Route 703 (Celina Road) and Ohio State Route 364 (Park Road), at 40°32′43″N 84°25′29″W.

Neptune is an unincorporated community in Mercer County, in the U.S. state of Ohio.

Bulkhead is an unincorporated community in Saint Marys Township, Auglaize County, Ohio, United States. It is located southwest of St. Marys on the eastern shore of Grand Lake along Ohio State Route 364, at 40°31′14″N 84°25′17″W.One of the Miami and Erie Canal feeder canals is located in Bulkhead.

Center Township is one of the fourteen townships of Mercer County, Ohio, United States. The 2020 census found 1,099 people in the township.

Franklin Township is one of the fourteen townships of Mercer County, Ohio, United States. The 2020 census found 2,511 people in the township.

Celina Senior High School is a public high school located in Celina, Ohio, United States. It is the only high school in the city. Their mascot is a bulldog. They are members of the Western Buckeye League. The average enrollment is around 1,100 students.

Montezuma is a village in Mercer County, Ohio, United States. The population was 152 at the 2020 census.

The Dr. Issac Elmer Williams House and Office are a pair of buildings in St. Marys, Ohio, United States. Built in 1903, both are fine examples of the Queen Anne style of architecture.Immediately after graduating from the Kentucky School of Medicine at the University of Louisville in 1892, Williams began to practice medicine in St. Marys; he remained there until retirement in 1942. He built his house and office on the city's western side in 1903; their location adjacent to each other was a typical arrangement at the time for doctors in small cities such as St. Marys. These two buildings, both frame, feature the Queen Anne style common in the early twentieth century. Among the leading architectural features of the house are its large roof with multiple gables, of which the most prominent are those of the attic that feature imbricated shingles on their walls. Located to the south of the house, the office is a five-room single-story structure. Its design is similar to that of the house, including an attic gable with imbricated shingles.In 1979, the house and office were listed together on the National Register of Historic Places. They qualified for inclusion on the Register both because of their contribution to local history and because of their architecture. As virtually no changes have been made either to the house or to the office — inside or out — they are excellent examples of early twentieth-century Queen Anne architecture, especially because of their location adjacent to each other. Moreover, these buildings are significant because of their place as a house-and-office combination of a typical early twentieth-century doctor.

Jefferson Township is one of the fourteen townships of Mercer County, Ohio, United States. The 2020 census found 13,802 people in the township.

Celina ( sə-LY-nə) is a city in and the county seat of Mercer County, Ohio, United States about 58 miles (93 km) northwest of Dayton. The population was 10,935 at the 2020 census. Celina is situated on the northwestern shores of Grand Lake St. Marys.

St. Marys is a city in Auglaize County, Ohio, United States. Located in western Ohio, it is 11 miles (18 km) west of Wapakoneta and 20 miles (32 km) east of the Ohio–Indiana border. Founded in 1823, the city is located on a portage between the St. Marys and Auglaize river systems, which was a significant factor in its development before the era of canals. The population was 8,397 at the 2020 census. It is included in the Wapakoneta micropolitan area.