Henichesk Strait
Ukraine
The Henichesk Strait is a narrow strait which connects the Syvash (the shallow lagoon system separating the Crimea from the rest of Ukraine east of the Isthmus of Perekop) with the Sea of Azov. It separates the Arabat Spit from the Ukrainian mainland.
Data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).