Thanks to Ivan Shishkov for the following information about the recent release (20 Jul 2018) by Bulgarian Posts of a souvenir sheet showing Burgas Lighthouse located at the north side of the entrance of the port of the same name in Bulgaria. The lighthouse is shown on the lower right portion of the sheet but not on the stamp. The sheet was issued on two types of papers, one ordinary and the other on paper with UV fibers. The UV version has serial numbers from 00001 to 001800 while the ordinary paper ones are numbered from 001801 to 003600.
See more lighthouse stamps from Bulgaria here