Agia Efimia is located in the northern tip of the Sami Gulf, on the east coast of Kefalonia, and is the capital of the former Municipality of Pylaros. The area of ​​Pylaros is bounded by the bay of Myrtos to the west, the mountains of Agia Dynati to the south and Kalon Oros to the north and the bay of Sami to the east. The villages of Pylaros are located on the slopes of the two aforementioned mountains, where a green valley with olive trees and vines is formed. Agia Efimia seems to have been the main port of the region for imports-exports and communication with other regions since long ago. Antiquities from the Roman era have recently been discovered, which show the existence of residential activity in this location, but whose ancient name is yet to be defined. In the Byzantine and medieval years, because this area was in danger of raids, no settlement is mentioned in any of the written sources that exist, nor in censuses made during the period of the Venetian occupation.For the first time the name "Agia Efimia" is mentioned as a toponym in this place at the end of the 17th century, by the Venetian cartographer Coronelli, but without mentioning a settlement with permanent residents. It seems that only the port was used for local trade. In the middle of the 18th century, it was decided by the Venetians to establish a sanatorium on the beach of Agia Efimia, in order to control mainly the locals, who during the summer months worked as harvesters in the Peloponnese and returned, but also other visitors, mainly traders from the mainland Hellas. Agia Efimia developed into an important settlement in the middle of the 19th century and from then until today it is the most developed village in the area. Around the same time, the ruined church of the same name was rebuilt by the archimandrite Sophronios Makris, which soon turned into a common house, and was completed with a small almshouse and a library. Today's settlement is particularly picturesque and has good infrastructure, which is why it is a destination for thousands of visitors in the summer.