Raseborg Castle

The ruins of Raseborg Castle are situated on what was originally a 14-meter-high rocky island within the Raseborg River. The waterway once provided direct access to the Gulf of Finland, allowing supply boats to reach the fortress. Due to natural land uplift following the last ice age, the river has largely receded, leaving the castle ruins approximately 50 meters from the current riverbank on dry ground. The fortress’s overall design resembles a horseshoe or an uppercase letter ‘D,’ with the curved side facing north, taking advantage of the cliff edges that rise 4 to 5 meters high on the northern and western sides. These steep cliffs acted as formidable natural defenses that required little additional fortification after the initial construction.

The castle’s interior was organized around a long, narrow rectangular courtyard, enclosed by stone foundations of residential and service buildings. These housed higher-ranking servants and guards, indicating a complex and hierarchical community within the walls. On the southern and eastern sides, an outer bailey was added in the mid-15th century, functioning as an additional defensive barrier. The bailey was protected not only by thick stone walls but also by a wide moat filled with water that stretched around the landward approach. This moat spanned roughly 300 meters in length and varied between 12 to 18 meters in width.

Raseborg’s defenses extended into the water as well, where wooden palisades—rows of sharpened stakes—were installed to block enemy ships from reaching the fortress directly. Some remnants of these underwater obstacles remain visible today. The castle’s gates were narrow and specially designed for delivery by boat, hinting at the significance of riverborne supply routes. Horses were notably kept offsite on an adjacent island known as Stallholmen, or Istállósziget, a settlement of local peasants supporting the castle.

One distinct feature from the late medieval renovation phase is the round residential tower, a multi-story stone structure with thick walls that served both defensive and living purposes. Although now partially restored, it offers a glimpse into the living conditions and architectural styles of the era. Excavations have also uncovered vaulted cellars, including a once-sturdy beer cellar that collapsed in 1558, which marks the material decline of the site. Wooden stairs, terraces, and railings reconstructed on-site approximate the original height of the castle walls, estimated at around 15 meters tall during its prime.

The complex extended beyond the fortified walls, with nearby peasant villages and, over time, a larger settlement established on the river’s northern bank. These communities provided essential services and supplies, supporting the castle’s function as a military and administrative hub over several centuries. Together, the ruins and surrounding archaeological traces tell the story of a fortress adapting to changing political and military challenges from the late Middle Ages through the early modern period.