Megalithic architecture appeared in what is now the Netherlands during the Neolithic period, especially in the northeast. Megalithic structures, i.e. buildings made of large upright stones, occur in various forms and functions, mainly as burial sites, temples or menhirs (stones standing alone or in a formation). In the Netherlands, only burial complexes are known. These large stone tombs () were built between 3470 and 3250 BCAnna L. Brindley: The typochronology of TRB West Group pottery. In: Palaeohistoria. Volume 28, 1986, p. 93–132 (online). JYears corrected according to Moritz Mennenga: Zwischen Elbe und Ems. Die Siedlungen der Trichterbecherkultur in Nordwestdeutschland (= Frühe Monumentalität und soziale Differenzierung. Volume 13). Habelt, Bonn 2017, , p. 93 (online). by members of the Western Group of the Funnelbeaker culture (TBK) and were used until about 2760 BC. After the end of the Funnelbeaker culture in the Late Neolithic, the sites were reused by the Single Grave culture and the Bell Beaker culture during the ensuing Early Bronze Age and, to a lesser extent, into the Middle Ages.Of the original 100 megalithic tombs in the Netherlands, 54 are still preserved today. Of these, 52 are located in the province of Drenthe. Two more are in the province of Groningen, one of which has been turned into a museum. There is also a site in the province of Utrecht whose classification as a megalithic tomb is uncertain. Destroyed megalithic tombs are also known from the province of Overijssel. Most of the surviving tombs are concentrated on the Hondsrug ridge between the cities of Groningen and Emmen.

The tombs attracted the interest of researchers early on. The first paper was published in 1547. A book published in 1660 by Johan Picardt, who believed that the tombs were the constructions of giants, was widely read. Titia Brongersma carried out the first known excavation of a Dutch megalithic tomb in 1685. In 1734, the first law was passed to protect the tombs, followed by others in the 18th and 19th centuries. In 1846, Leonhardt Johannes Friedrich Janssen published the first nearly complete inventory of the tombs. In 1878, William Collings Lukis and Henry Dryden made the most accurate plans to date of many of the graves. Modern archaeological research on the megalithic tombs was initiated in 1912 by Jan Hendrik Holwerda, who completely excavated two sites. Shortly thereafter, Albert Egges van Giffen began further research. He measured all the sites, carried out numerous other excavations, and had almost all the graves restored by the 1950s. Van Giffen also developed a numbering system for the megalithic tombs that is still used today, with a capital letter for the province and a number ascending from north to south (and a lowercase letter for destroyed sites). Since 1967, there has been a museum in Borger dedicated exclusively to the megalithic tombs and their builders.

The chambers of the tombs were built of granite boulders deposited in the Netherlands during the Ice Age. The gaps between the stones were filled with dry stone made of small stone slabs. The chambers were then covered with earth. Some of the mounds also have a stone fence. Depending on whether the entrance to the chamber is on a long or narrow side, the graves are called dolmens or passage graves. Almost all sites in the Netherlands are passage graves, only one is a dolmen. The graves are similar in their basic structure but vary greatly in size. The length of the chamber ranges from 2.5 m to 20 m. Small chambers were built in all phases of construction, while larger ones were added only in later phases.

Due to the unfavorable preservation conditions, only small amounts of human bones were recovered from the graves. These were mainly cremated remains. Only very limited information is available on the age and sex of the deceased.

In contrast, the grave goods were exceedingly rich. In some graves, thousands of pottery shards were discovered, which could often be reconstructed into hundreds of vessels. Other grave goods included stone tools, jewelry in the form of beads and pendants, animal bones, and, in rare cases, bronze objects. The diverse array of vessel forms and decorations permitted the identification of multiple typological levels, thereby enabling insights to be gleaned about the construction and utilization history of the graves.

Research history

Early research (16th-18th century) The modern study of the Dutch megalithic tombs commenced in 1547 with Anthonius Schonhovius Batavus (Antony van Schoonhove), canon of the St. Donatian's Cathedral in Bruges. In a manuscript, he referenced a passage in Tacitus' Germania in which "Pillars of Heracles" are mentioned in the land of the Frisians. Schonhovius equated these with one of the tombs near Rolde and mixed Tacitus' text with local legends. He assumed that the building material was brought here by demons who were worshipped under the name of Heracles. He also believed that the tombs were altars on which human sacrifices were performed. His text was subsequently adopted by numerous other scholars over the following decades, with the Pillars of Heracles or the "Duvels Kut" ("Devil's Cunt", another name used for the grave near Rolde according to Schonhovius) being recorded on several maps between 1568 and 1636.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 36–38.

It was more than a hundred years before anyone wrote about the Dutch megalithic tombs who had seen them. Johan Picardt, a native of Bentheim, worked as a pastor in Rolde and Coevorden, among other places, and was also responsible for the colonization of the bogs in the border region between Bentheim and Drenthe. In 1660, he published a three-part work on the antiquities of the Netherlands, particularly the province of Drenthe and the town of Coevorden.Johan Picard: Korte Beschryvinge Van eenige Vergetene en Verborgene Antiquiteten Der Provintien en Landen Gelegen tusschen de Noord-Zee, de Yssel, Emse en Lippe. Goedesbergh, Amsterdam 1660 (online). Picardt's views were strongly influenced by biblical stories. For example, he hypothesized that the megalithic tombs were built by giants who had migrated to Drenthe from the Holy Land via Scandinavia. This view became widespread, not least because of the impressive illustrations in Picardt's book. At the same time, before and during Picardt's lifetime, there were other (mainly German) researchers who rejected this idea and attributed the construction of the tombs to ordinary people.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 41, 44–48. Picardt was also the first to provide detailed descriptions of the structure of the tombs and to mention ceramic vessels as burial objects.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 49–50.

The lawyer and historian Simon van Leeuwen also visited the megalithic tombs in the province of Drenthe a few years after Picardt and dedicated a section to them in his work Batavia Illustrata,Simon van Leeuwen: Batavia Illustrata, Ofte Verhandelinge vanden Oorspronk, Voortgank, Zeden, Eere, Staat en Godtsdienst van Oud Batavien, Mitsgarders Van den Adel en Regeringe van Hollandt / Ten deele uyt W. Van Gouthoven, en andere Schryvers, maar wel voornamentlijk uyt een menigte van oude Schriften en Authentijque Stukken en Bewijsen, Te samen gesteldt door de Heer Simon van Leeuwen, In sijn leven Substituyt Griffier vanden Hogen Rade van Hollandt, Zeelandt, en Westvrieslandt. Veely, 's-Gravenhage 1685. published posthumously in 1685. Van Leeuwen also considered the possibility of giants as builders, but thought more of tall Cimbri and Celts.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 51–52.

Titia Brongersma, a poet from Dokkum, conducted the inaugural known excavation of a megalithic tomb in the Netherlands in 1685. In collaboration with her cousin Jan Laurens Lentinck, the Schultheiß of Borger, she spearheaded the investigation of the Borger megalithic tomb (D27). Brongersma herself only published two poems about it, from which it emerges that she believed the grave was a temple dedicated to nature. However, she discussed this intensively with her friend Ludolph Smids, a doctor and poet from Groningen. Smids initially wrote a poem about the excavation. He published these poems in his work Poëzije in 1694 and also added a more detailed description of the finds and discoveries from the grave. Smids' publication of the excavation in Borger and his correspondence with Christian Schlegel led to the idea of giants as the builders of the megalithic tombs being increasingly rejected.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 54–56. However, Smids himself revised his views again after his conversion from Catholicism to Calvinism and again took up Picardt's views in his work Schatkamer der Nederlandse oudheden, published in 1711.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 59–60.

In 1706, Johannes Hofstede and Abraham Rudolph Kymmel conducted another excavation at a large stone tomb in Rolde (D17). In his report, Hofstede described the different layers within the site and the stratigraphic position of the pottery found. Unfortunately, the report did not influence Hofstede's contemporaries, as it was not published until 1848.Petrus Speckman van der Scheer: In: Kronijk van het Historisch Gezelschap te Utrecht. Volume 4, 1848, p. 190–192 (online).Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 57, 59.

In the 1730s, new levees were constructed in significant portions of the Netherlands and northwest Germany, replacing the previous ones, which were based on wooden structures that had been damaged by imported shipworms. The new dikes consisted of stone-covered earth mounds, which is why erratic blocks became a highly sought-after building material. The unregulated search for erratic blocks also led to the removal of boundary stones. This prompted the government of Drenthe to issue a resolution on July 21, 1734, prohibiting such actions. At the same time, this resolution placed the megalithic tombs under protection. After two royal decrees in Denmark (1620) and Sweden (1630), this was the third law to protect antiquities in Europe.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 60, 62–63.

In 1732, the affluent Amsterdam textile merchant Andries Schoemaker undertook a journey to Drenthe with the draughtsman Cornelis Pronk and his apprentice Abraham de Haen. This excursion resulted in the initial realistic depictions of the two megalithic tombs situated in the vicinity of Havelte (D53 and D54). Schoemaker also furnished a comprehensive account of the sites. Both draughtsmen subsequently returned to Drenthe. Two surviving drawings by Abraham de Haen of the megalithic tomb D53 from 1737 and one by Cornelis Pronk of the megalithic tomb Midlaren (D3) from 1754 provide insight into the evolution of these structures.Jan Albert Bakker: Megalithic Research in the Netherlands, 1547–1911. 2010, p. 64–66.