Earthworks (archaeology) in the context of "Ringwork"

In the history of the Americas, the pre-Columbian era, also known as the pre-contact era, or as the pre-Cabraline era specifically in Brazil, spans from the initial peopling of the Americas in the Upper Paleolithic to the onset of European colonization, which began with Christopher Columbus's voyage in 1492. This era encompasses the history of Indigenous cultures prior to significant European influence, which in some cases did not occur until decades or even centuries after Columbus's arrival.

During the pre-Columbian era, many civilizations developed permanent settlements, cities, agricultural practices, civic and monumental architecture, major earthworks, and complex societal hierarchies. Some of these civilizations had declined by the time of the establishment of the first permanent European colonies, around the late 16th to early 17th centuries, and are known primarily through archaeological research of the Americas and oral histories. Other civilizations, contemporaneous with the colonial period, were documented in European accounts of the time. For instance, the Maya civilization maintained written records, which were often destroyed by Christian Europeans such as Diego de Landa, who viewed them as pagan but sought to preserve native histories. Despite the destruction, a few original documents have survived, and others were transcribed or translated into Spanish, providing modern historians with valuable insights into ancient cultures and knowledge.

Many pre-Columbian cultures in North America were collectively termed "Mound Builders", but the term has no formal meaning. It does not refer to specific people or archaeological culture but refers to the characteristic mound earthworks that indigenous peoples erected for an extended period of more than 5,000 years. The "Mound Builder" cultures span the period of roughly 3500 BCE (the construction of Watson Brake) to the 16th century CE, including the Archaic period (Horr's Island), Woodland period (Caloosahatchee, Adena and Hopewell cultures), and Mississippian period. Geographically, the cultures were present in the region of the Great Lakes, the Ohio River Valley, Florida, and the Mississippi River Valley and its tributary waters. Outlying mounds exist in South Carolina at Santee and in North Carolina at Town Creek.

The first mound building was an early marker of political and social complexity among the cultures in the eastern part of what is now the United States. Watson Brake in Louisiana, constructed about 3500 BCE during the Middle Archaic period, is the oldest known and dated mound complex in North America. It is one of 11 mound complexes from this period found in the Lower Mississippi Valley.These cultures generally had developed hierarchical societies that had an elite. These commanded hundreds or even thousands of workers to dig up tons of earth with the hand tools available, move the soil long distances, and finally, workers to create the shape with layers of soil as directed by the builders. However early mounds found in Louisiana preceded such cultures and were products of hunter-gatherer cultures.

A platform mound is any earthwork or mound intended to support a structure or activity. It typically refers to a flat-topped mound, whose sides may be pyramidal.

The Danevirke or Danework (modern Danish spelling: Dannevirke; in Old Norse: Danavirki, in German: Danewerk, literally meaning earthwork of the Danes) is a system of Danish fortifications in Schleswig-Holstein, Germany. This historically important linear defensive earthwork across the neck of the Cimbrian peninsula was initiated by the Danes in the Nordic Iron Age about AD 650. It was later expanded multiple times during Denmark's Viking Age and High Middle Ages. The Danevirke was last used for military purposes in 1864 during the Second War of Schleswig.

The Danevirke consists of several walls, trenches and the Schlei Barrier. The walls stretch for 30 km, from the former Viking trade centre of Hedeby near Schleswig on the Baltic Sea coast in the east to the extensive marshlands in the west of the peninsula. One of the walls (named Østervolden), between the Schlei and Eckernförde inlets, defended the Schwansen peninsula.

The Benin Moat (Edo: Iyanuwo), also known as the Benin City Iya, the Inner City Iya of Benin or the Wall of Benin, is a large earthwork within Benin City in Nigeria's Edo state, which formerly encircled the city at the time of the Benin Empire. It is the central part of a series of connected earthworks surrounding the city which are collectively known as the 'Benin City Walls', consisting of the massive Inner City earthwork and much smaller, though more extensive Outer City earthworks. Other earthworks are spread out across Edo State (known as the rural iya), and all of these earthworks are sometimes referred to collectively as 'the Walls of Benin'. All of these earthworks are known as Iya in the Edo language. With the exception of a small part of the Benin City Iya, these structures are not really 'walls' but rather linear earthworks, consisting of a ditch and earth rampart known as a 'dump rampart'. The Inner City Iya was built on a significantly larger scale with much taller ramparts and deeper ditches than any of the surrounding earthworks or other earthworks spread across the country, many of which are described as having a 'slight' and 'casual' profile. Most of these earthworks only served to delineate boundaries, whereas the Inner City Iya served a defensive purpose. Historical European accounts of the 'Benin Moat' or 'Benin City Wall' probably only refer to the Inner City Iya, though the accounts sometimes differ in their description of its structure. Several wooden entrance gates are said to have existed, but 19th century accounts make no mention of them and their remains have yet to be identified by archeological research. The Inner City Iya had a total length of approximately 12 kilometres (7.45 miles), though much of it has disappeared due to urban expansion and destruction in the modern era. The combined length of all of the earthworks across the entire country, including ditches and ramparts and boundary traces, has been estimated to be approximately 16,000 kilometres (9,900 mi), covering about 6,500 square kilometres (2,500 sq mi) of land, though little remains today. Whilst some sources have erroneously referred to these earthworks as comprising a single built structure, they actually consist of many different structures created at different times, some of which are connected and others which are not. These earthworks have deep historical roots, with evidence suggesting their existence before the establishment of the Oba monarchy. Construction may have begun as early as 800 AD, continuing up to the modern era. The Inner City Iya itself was built in c. 1460 AD. Its construction involved large-scale manual labour and the repurposing of earth from the outer ditch to build the inner rampart. It is estimated that a labour force of 5,000 men, working 10 hours a day, could have completed the work in 97 days, within the period of a single dry season.

Today, remnants of the Iya can still be found in Benin City, although urbanisation and land disputes pose challenges to their preservation. Recognised for their historical significance, the Benin Iya have been placed on a tentative list of Nigerian World Heritage Sites, though they have yet to be included in the official list by UNESCO. The Guinness Book of World Records describes 'The Linear Earthworks of Benin and Isha' as "the longest earthworks of the pre-mechanical era", though this refers to the estimated length of all the earthworks and boundary traces across the country combined and not specifically to the moat and rampart surrounding Benin City.