SV. IVAN LTHO, GPS 42°26.30'N; 027°41.44'E

Sv. Ivan Island Lighthouse is located on the highest part of the largest Bulgarian island - Sv. Ivan. The lighthouse was built in December 1883 by the French company "Collas & Michel". In 1888, the optics were replaced by newer ones made by the French company "Barbier, Bénard & Turenne", replaced by even newer ones in 1911. The height of the lighthouse was 13,0 m (without the wind indicator).

In 1931, a 5 m high concrete pedestal was erected 25 m north-east of the light tower, on which a nautophone made by the German company "Julius Pintsch" (Berlin) was mounted. It is used to send signals during fog. It features: 3 sec tone, 2 sec pause, 3 sec tone, 2 sec pause, 3 sec tone, 12 sec pause.

From 18 July 1953 the light source was oil gas with a "Julius Pintsch" burner. The first accumulators were delivered in 1957 and replaced in 1975 together with the delivery of a diesel unit. In August 1972, an untimely hailstorm shattered the glass of the lantern and some of the optics. The optical system was then replaced with fixed cylindrical optics. The last modernization of the lighthouse was made in 2014, and a photovoltaic panel "SM-20P4" with an LED illuminator with autonomous solar power supply was installed.

The light emitted from the beacon is white, group-flashing, with a periodicity of 10 sec (light - 0.5 sec, dark - 2.0 sec, light - 0.5 sec, dark - 7.0 sec), with a visibility of 20 nautical miles.