Kostrena is a Croatian municipality situated east of Rijeka on the Kvarner Bay. It serves as an industrialized suburb of Rijeka, hosting significant infrastructure such as an oil refinery and an oil power plant at Urinj, as well as the Viktor Lenac shipyard located in the bay of Martinšćica.
The area is known for its long tradition of seafaring and seamanship. It is a popular destination for recreation and sports due to its rocky beaches and a coastal walkway. Notable landmarks include the Trim-staza, a scenic hill walk on the northeast side of the municipality, and archaeological sites containing ruins from the Roman era.