Curonian Spit (Lithuanian: Kuršių nerija, Russian: Куршская коса, German: Kurische Nehrung, Latvian: Kuršu kāpas)

Depends what nationality u are. As an EU-citizen, go ahead through EU countries Latvia, Lithuania, Poland , Estonia. You need a passport and visa for the Russian part (Kaliningrad) and need to obtain that beforehand in your home country (no visa issued in neighboring countries). This concerns individual tourists like you (package tourists with pre-booked hotels can obtain a 72-hrs-visa at the border). There`s a WS host in Kaliningrad who might give u more info.