Question: What is the largest city on the Caspian Sea and of the Caucasus region, has a railway line in the station in a settlement in the municipality of Nakhchivan in Nakhchivan City, Nakhchivan Autonomous Republic, Azerbaijan?
Sentence (from "Baku"): Baku is located 28 m below sea level, which makes it the lowest lying national capital in the world and also the largest city in the world located below sea level.
Relevant evidence: No