Mouth of the Curonian Lagoon and Klaipėda Harbor

The natural spectacle is a peninsula on the coast of Lithuania, characterized by unique dune landscapes and fine white sandy beaches. It has been a UNESCO World Heritage Site since 2000 and is affectionately known by the locals as the “Pearl of the Baltic Sea” or “Lithuanian Sahara”. A border with Russia runs in the middle of the Curonian Spit. A total of 52 km of the headland belong to the Lithuanian side. The entire spit has been declared a national park. In this way, the unique natural and cultural landscape is also sustainably preserved for the future.
Source: DFDS Germany

on the one hand a great beach, on the other hand the harbor

Unfortunately you are not allowed to enter the pier. (generally not or only prohibited because of the construction work)