MASLEN NOS LTHO, GPS 42°18.48'N; 027°47.59'E

Maslen nos lighthouse was commissioned on 25 July 1932, having previously been an oil lantern with constant light. The lighthouse tower is a 7 metre high cylindrical stone masonry tower painted white. The distance from sea level to the top of the lighthouse optics is 37 m. The lighthouse has a "Julius Pintsch" rotating light installation.

To the south of the light tower is a stone cabin, 3 metres high, on which is placed a bronze bell. The bell houses the mechanism. The signal is set in motion manually. Features: ring, pause 3 sec, ring, pause 6 sec and repeat. Sound spread - 1,5 nautical miles. Duration of one winding of the mechanism - 2 hours. The signal was in operation from 30 June 1937 to 1981.

Since 1961, a radio beacon type "KRM - 100" (USSR), with call signs "M-H" (– –, – .) began operating from the territory of the Maslen nos lighthouse. The range of action is up to 100 nautical miles.

In 1968, the light was replaced by a light head "EM-500", and in 1976 the light was electrified. In the period 1980-1981, the most modern automatic illuminated lighthouse in Bulgaria at that time was installed on Maslen Nos. The replacement of burnt bulbs and the changeover from main to emergency power supply and vice versa was fully automatic. The beacon optics are now "ASA-500M" and measurements made show that the beacon light can be seen up to 20 miles out to sea. In 2013, the last upgrade was made when a photovoltaic panel "SM-20P4" with LED illuminator with autonomous solar power supply was installed on the lighthouse.

The light emitted from the beacon is white, group-flashing, with a periodicity of 17.2 sec (0.4 sec - light, 4 sec - dark, 0.4 sec - light, 4 sec - dark, 0.4 sec - light, 8 sec - dark). Lighting sector - circular 360°, visibility - 17 nautical miles.