The park contains the largest number of islands in any archipelago worldwide, numbering in the thousands.
The landscape is physically rising out of the sea due to post-glacial rebound at a rate of approximately 5–6 millimeters per year.
Traditional farming methods, including pollarding trees and grazing, are actively practiced on several islands to preserve biodiversity.
The Archipelago Sea Biosphere Reserve was the first of its kind established in Finland by UNESCO in 1994.
The area is home to the endangered Baltic ringed seal, which requires ice cover to breed and protect its pups.
Several islands house historic wooden lighthouses and pilot stations that predate the establishment of the national park.
The park's brackish water environment supports a unique biological community distinct from both freshwater lakes and the full-salinity Atlantic ocean.
Archipelago National Park comprises the world's largest archipelago by number of islands, spanning 500 square kilometers of water and land in the Baltic Sea. The park is managed by Metsähallitus and is part of the UNESCO-designated Archipelago Sea Biosphere Reserve. It encompasses over 2,000 islands and skerries, ranging from larger inhabited islands to small, barren rocks. The landscape features a mix of traditional cultural habitats, such as wooded meadows and pastures, alongside open sea and rocky coastal environments. Its unique geography is formed by glacial retreat, leading to continuous land uplift. The park serves as a critical habitat for Baltic seals, white-tailed eagles, and numerous migratory bird species. Water quality is heavily monitored to maintain the health of the sensitive brackish ecosystem. Visitors primarily access the park through ferry routes from Kasnäs or other neighboring harbors. The park maintains a network of campfire sites, boat harbors, and marked nature trails across select islands.
The elevated rocky outcrops on Örö Island provide panoramic views of the open Baltic horizon.
Bring a high-quality windbreaker and sturdy, non-slip footwear, as rocky terrain can be slippery and weather conditions shift rapidly.
Ensure your mobile phone is fully charged and store it in a waterproof bag, as charging facilities are nonexistent on remote islands.
Familiarize yourself with 'Everyman's Rights' to understand legal boundaries regarding camping, foraging, and fire safety in Finnish nature.
Attempting to visit remote skerries during the spring nesting season, as landing is strictly prohibited to protect local bird populations.
Ferry services and visitor center operations are significantly reduced or suspended during the winter months.
Strictly follow Leave No Trace principles; keep dogs leashed, use only designated campfire sites, and never disturb nesting birds.
