Derna ˈdɜrnə is a port

Port

A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land....

 city in eastern Libya

Libya

Libya is an African country in the Maghreb region of North Africa bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west....

. It has a population of 80,000. It was the seat of one of the wealthiest provinces in the Barbary States, and remains the capital of the Derna District, with a much smaller area. Derna has a unique environment among Libyan cities, as it lies between green mountains, the Mediterranean Sea, and the desert. The city is also home to people of mixed origins.
Darnis and Darne were the Greek forms of the name for the city, while sometimes the form Dardanis is found, it was due to an error.