There are four open settlements in its immediate vicinity; three of them were functioning at the same time as the ring fort; (site 2, 3, 5).

Location and description

The ring fort is located aroun 1,200 metres to the west of the centre of the village of Słupno, 200 metres to the south of the bed of the Słupianka stream It is situated on a floodplain terrace of the Vistula River, on a small elongated sand mound surronded by waterlogged areas. The settlements were located on small raised area of land: settlement 2 in the foreground of the ring fort to the north and north-west, settlement 3 to the south-east of the ring fort, and settlement 5 to the east of it.

The ring fort has an oval shape and measures around 90 m by 75 m. The rampart is up to 25 m in width at the base and up to about 4 m in height. Its eastern part features a saddle-shaped depression, where an entrance gate to the ring fort was probably originally located. The site is overgrown with trees to the extent that it is visible. The area of the ancillary settlements adjacent to the fort is used as arable land.

History

Wojciech Szymański dates the ring fort to the 11th century. The findings from research projects indicate that the ring fort was built on the site previously occupied by a settlement of the Lusatian culture from the Hallstatt period (c. 1,000-400 BC). The aforementioned ancillary settlements adjacent to the fortified centre date back to the 10th-11th c. (site 3, 5) or the 11th c.

Condition and results of archaeological research

The ring fort in Słupno has been known since the 19th century. It was mentioned in field reports drawn up in the 20s. The first inventory research and verifications of the ring fort were carried out in 1959. Surveys under the supervision of Wojciech Szymański were conducted in 1966. The ancillary settlements adjacent to the ring fort were investigated in 1966 (site 2) and 1975 (site 5). In 1982, the ring fort was registered during the surface surveys carried out within the framework of the “Archaeological Picture of Poland” project.

Two excavations which intersected in the centre of the ring fort cut through it along the north-south axis and east-west axis; the third excavation was undertaken in the area of the ancillary settlement adjacent to the ring fort on the north side. Cultural layers, i.e., accumulations of man-made soil, were discovered only in the section along the rampart. An investigation of the northern side revealed a cultural layer under the embankment, i.e., a layer older than the rampart, containing fragments of Lusatian ceramics. Fragments of early medieval ceramics associated with the functioning of the ring fort were found in the southern part. The chronology was confirmed by the finds made in the area of the ancillary settlements adjacent to the fortified centre. In 1966, archaeologists investigated seven storage pits in the area of settlement 2. Six of them which contained fragments of ceramics and animal bones date back to the Early Iron Age (650-400 BC). The last one with monument dating from the 11th century (fragments of ceramic vessels and roasters in the form of quadrangular clay vessels used for roasting cereal grains) was initially construed by Wojciech Szymański as a smokehouse. Investigations of settlement 5 conducted in 1975 uncovered poorly preserved traces of residential buildings, hearths and storage pits, dating from the 11th-12th centuries, as determined based on the finds (spindle whorls, fragments of knives and horn knife holder, comb, amber bead, and pottery). Researchers also found a waste pit and a grave, dating from the end of the Lusatian Culture, i.e., the Early Iron Age. Excavations of the site also unearthed ceramics from the period of Roman influence (1st-4th c. AD)

The ring fort is located in the vicinity of a developing housing estate with one-family houses. An access road runs near the ring fort.

Compiled by Agnieszka Oniszczuk, National Heritage Board of Poland, 23.08.2014 r.

Bibliography

• Przybysz K., Słupno, gm. Borowiczki, woj. płockie. Stanowisko 5, „Informator Archeologiczny”, Badania rok 1975, 1976, p. 209.
• Miśkiewiczowa M., Mazowsze płockie we wczesnym średniowieczu, Płock 1982, pp. 51-62, 167-168, 221, 272-274.
• Szymański W., Sprawozdanie z badań sondażowych na grodziskach w Dźwierznie, Karwosiekach, Słupnie, pow. Płock, Huszlewie, pow. Łosice, Krzesku-Królowej Niwie i Podnieśnie, pow. Siedlce, w 1965 roku, „Sprawozdania Archeologiczne”, vol. XIX , 1968, pp. 177-181.
• Szymański W., Osadnictwo wczesnośredniowieczne z XI-XII w. w rejonie Słupna, pow. Płock, „Wiadomości Archeologiczne”, Vol. 36, issue 2, 1971, pp. 230-231.
• Szymański W., Słupno, st. 1, gmina Borowiczki (d. pow. Płock), woj. płockie, [in:] Grodziska Mazowsza i Podlasia (w granicach dawnego województwa warszawskiego), collective work, Wrocław -Warszawa -Kraków -Gdańsk, 1976, pp. 122-125.