Harbor Mesolonggiou is formed by a diamond-shaped dredged basin with a width of 800 m and a length of 1000 m. The coasts of the harbor are quayed for about 562 m and have depths of 2.9–8.6 m near them. There are two ramps: one on the NE and one on the SE side. At the north shores of the harbor the homonymous fishing shelter is located.