Crescent Hill is one of Louisville's oldest and most well-known neighborhoods. Located four miles east of downtown Louisville, it stretches from Ewing Avenue to the Masonic Home and is bisected by Frankfort Avenue, its principal commercial corridor. Frankfort Avenue parallels the CSX railroad line that was, in the 1850s, the impetus for the development of what became the neighborhood. Originally the site of the state fairgrounds, Crescent Hill was known as Fair Grounds, but the present name first appeared in the 1870s after the fairgrounds were sold. In the late 19th century, Crescent Hill was the site of estates that served as summer homes for many of Louisville's elite. An independent municipality from the 1880s until Louisville annexed it in the early 20th century, the neighborhood was gradually subdivided into smaller lots with pleasant homes, many of which remain today. In addition, Crescent Hill is the home of the Louisville Water Company's filtration plant and reservoir—an iconic presence in the city.