The eastern part of the Gulf of Finland has always been considered difficult to navigate. Shallow depths, many sandbanks and rocky cans create dangerous conditions for navigation. That is why the first lighthouse structures appeared on Kotlin even under Peter I. Starting in 1712, navigation fires began to burn at its western end, and in 1719, the first wooden lighthouse, later called Tolbukhin, appeared west of the island. In the same year, on the approach to Kronstadt near the southern coast of the Gulf of Finland, two Russian battleships Portsmouth and London crashed. Portsmouth’s remains were not found then, on the skeleton of the ship “London” they built an impromptu lighthouse, which existed until the 30s of the XVIII century. The next stage of the construction of the Kronstadt lighthouses is associated with the name of L. V. Spafaryev, who was the director of the Baltic lighthouses in the beginning of the 19th century. It was under his leadership in 1810 that the lighthouse Tolbukhin was first rebuilt in stone. In the years 1862-1863. on the first bastion of the Military harbor, a small openwork lighthouse on six pillars, called the “Friedrichstadt”, was erected. Interestingly, this building has survived to the present day, and in fact is the oldest operating lighthouse on the island. At Fort Kronslot you can see two more lighthouses – Nikolaev Sights. Their metal towers at the end of the 19th century were made at the factory of Franz Karlovich San Galli in St. Petersburg. The highest navigation marks in the water area of the island were built at the beginning of the 20th century – this is the Kronstadt lighthouse 54 meters high and the back section of the Sea Canal, which rises 45 meters above the bay.