For a few euros you can hop on the ferry boat at the Helsinki City Harbour and immerse yourself for a few hours at this cultural UNESCO heritage.

Suomenlinna Sea Fortress, located in Finland, is a historic gem with roots dating back to the mid-18th century. This site offers a fascinating blend of Swedish, Russian, and Finnish history, making it a must-visit destination for history buffs and curious explorers alike. You can buy tickets online.