The ruins of the ancient Sibbesborg Castle are located on the west bank of the Sipoonjoki River in Söderkulla. The medieval castle was built on what was once an island, now surrounded by fields. At the site, you can see moats as well as the remains of the building’s foundations and brick walls. Recent research dates the castle to the late 14th century; its original name and the exact builder are unknown. The municipality of Sipoo confirms that the remains of the ramparts are open to the public. A sign along Uusi Porvoontie, west of the Kallbäck Bridge, points the way to the site. The visiting address is Uusi Porvoontie 1071, and the map marker is located within the actual ancient castle area. This is an outdoor site that visitors explore on their own. The edges of the cliff are steep in places. The structures and terrain of the ancient site must be protected. The area is owned by the Sibbo Local History Society; you can request additional information via their general email address.