Corinthia ( - Korinthía) is one of the regional units of Greece. It is part of the region of Peloponnese. It is situated around the city of Corinth, in the north-eastern part of the Peloponnese peninsula.
From 1833 to 1899, the Corinthia prefecture included Argolis and was known as Argolidocorinthia. It included Hydra, Spetses and Kythira. Argolis joined Corinthia to reform Argolidocorinthia again in 1909. Forty years later, in 1949, the prefecture was finally separated from Argolis.
The highway was first paved at the turn of the 20th century. The mid to late-20th century saw the population shifting from agriculture to other jobs, as people migrated to larger towns and cities as well as other parts of the world. In the 1960s, the motorway GR-8A was constructed to handle the increasing traffic between Corinth and Athens and allow higher speed limits (60 km/h to 80 km/h). The section from the old Corinth interchange eastward in Corinthia was opened in 1962 and the section west of Corinth was added in 1969. The new highway had a significant effect on the local industry, as it lowered the cost of transportation of goods between Corinthia and the Athens metropolitan area.
In late 2006, the prefect of Corinthia announced the construction of a new dam, to be located 5 to 7 km south of Kiato and Sicyon, near Stimanika, over the Elissos River. It will be the second largest body of water (lakes, reservoirs) in Corinthia. The dam will be designed to withstand earthquakes and natural disasters, including flooding.
On July 17, 2007, a forest fire struck the area around the historic Acrocorinth and its castle.