The lighthouse of Agios Theodoros is located in the Lassi area near Argostoli in Kefalonia and is one of the main attractions of the area. Built on an artificial peninsula, it takes its name from the homonymous church located nearby. It stands out for its special architecture, which makes it unique in its kind. It is a circular building, Doric style with 20 white columns and a tower 8 meters high with a focal height of 11 meters.

It is a romantic spot, ideal for taking nice photos and receives a lot of visits from both tourists and locals, especially at sunset, since the sunset from the spot is spectacular.

It was built in 1825 when the island was under the rule of the English and the administration of Charles Napier. It joined the Greek ferry network in 1863 with the annexation of the Ionian Islands to Greece. During the Second World War the lantern remained off, while it was reactivated in 1945 as a watchtower, with oil as an energy source. It was destroyed in the earthquakes of 1953 and rebuilt under the supervision of the Greek architect Takis Pavlatos in 1964, according to the original architectural plan.

In 1953 the oil machines were replaced with an automatic acetylene torch. In 1995, the lighthouse was declared preserved by the Ministry of Culture and today it is a historical monument of modern Greece.