Sammallahdenmäki is a Bronze age burial site including 36 granite burial cairns dating back more than 3000 years, from 1500 to 500 BC. Sammallahdenmäki is an exceptionally valuable example of Finland’s Bronze Age culture because it presents the ancient monuments in a well-preserved natural milieu. It’s designated as the UNESCO World Heritage Site in 1999.
Two of the most spectacular cairns are the quadrangular "Chuch Floor" and the dike-like "Long Ruin of Huilu". A typical feature of the Sammallahdenmäki cairns are the stone cists, boxlike structures formed by stone flags standing on edge and forming end and side walls or only one or the other. The cist may have originally contained a body in a wooden coffin, or the dead person may have been wrapped in animal skins. On the other hand, the cist may also have served as a receptacle for the ashes of a cremation burial. Remains of cists are still visible in some of the unexcavated cairns as well as in one cairn reconstructed after investigations.
Direction signs guide the visitor to Sammallahdenmäki from Highway 12 (Rauma–Huittinen). At the township of Lappi, the route turns north along Road 2070. After ca. 3.5 km the route turns left along a side road marked by a direction sign. The route ends at an information sign.
The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.