Iso Linnamäki

Iso Linnamäki is a medieval castle site perched on a hilltop in Porvoo with visible earthwork remains and stone foundations scattered across the slope. The location commands views over the river valley and the old town below, making its defensive position clear to visitors who walk the grounds.

The fortress was built around 1300 during Swedish efforts to expand control eastward into Finland. Excavations between 2007 and 2009 uncovered military and residential remains that connected this site to broader Scandinavian defensive networks of the period.

Information boards throughout the castle grounds detail the evolution of Finnish defensive structures from the Middle Ages through the Great Northern War.

The site is open year-round with free access and walking paths that lead across the hilltop. Winter visitors should expect unmaintained paths that become slippery or difficult to navigate during snow or ice.

Excavations uncovered crossbow bolts, medieval knives, pliers, and pottery fragments that reveal how the site served as both a residence and military station. These objects offer glimpses into daily life for the people who occupied this place in the 13th century.

Location: Porvoo

Part of: Old Porvoo

GPS coordinates: 60.39975,25.65220

Latest update: December 8, 2025 21:01