We are preparing organised trips to the sea-side (the wonderful Curonian Spit) and in Kaliningrad, in the meantime fyou will find here some information, as "appetiser":
Hashanna´s article gives you an overview of places to see:
Touristic websites with sightseeing information:
https://visit-kaliningrad.ru/en/charm/sea.php
https://visit-kaliningrad.ru/en/entertainment/sights/
http://www.inkaliningrad.com/tours/tours-in-kaliningrad-region/
http://www.inkaliningrad.com/tours/city-tours/
Information in German:
https://de.rbth.com/reisen/2014/06/07/ostseeflair_in_kaliningrad_29853
https://visit-kaliningrad.ru/de/