Large complexes of mounds and earthworks have been found throughout the Belle Glade culture area. Smaller complexes of earthworks and mounds have often been found associated with hammocks, and occasionally in wet prairies. Mound and earthworks sites were often adjacent to
sloughs or canoe trails. Robert Carr classified Belle Glade earthworks in three groups: linear ridges, circular-linear earthworks, and circular earthworks. Linear ridges are ridges or embankments created by piling dirt from ditches. They range from 15 to 730 metres in length. The ridges may be individual or in parallel groups. Ridges typically are found on savannahs or flood-plains that would have been periodically flooded during late pre-historic times. Linear ridges also occur as part of circular-linear earthworks. Circular-linear earthworks consist of curved ridges or embankments in the shape of a semi-circle, crescent, or horseshoe, usually with linear ridges radiating out from the curved ridge. Most of the sites are large, covering dozens of acres. Big Mound City and Tony's Mound are circular-linear earthworks.
Radiocarbon dates for samples from the linear and curved ridges at Fort Center fell in the period 600 to 1400. Circular earthworks are ridges or embankments that form a circle or nearly complete circle, usually with an adjacent ditch. They range from 61 to 366 metres in diameter. Samples from the circular earthworks at Fort Center fell in the period 1000 to 450 BCE. William Johnson expanded that classification system using mounds, ditches, borrows, and embankments as elements. Groupings of those elements variously appear in circular ditches, circular-linear earthworks (types A and B), linear embankments, square-rectangular earthworks, and mound groups.
Elements Mounds are found throughout the Belle Glade area. Middens were primarily habitation sites. Some constructed mounds were used for burials, while others appear to have been architectural elements in larger earthworks. Some mounds contained few, if any artifacts. Others held sherds, shell tools, projectile points, and human teeth, and some of the latest constructed mounds held objects made of metals recovered from Spanish shipwrecks. Ditches have been found forming circles and rectangles. Many of the ditches had berms on one or both sides. Many of the ditches are interrupted by short unexcavated segments termed "causeways". Two rectangular and one "square" ditch have been found near the Kissimmee River in Okeechobee County. Another type of ditch, canals suitable for canoes, have been identified in southern Florida. In the Belle Glade culture area, two such canals connect the
Ortona site to different points on the Caloosahatchee River.
Borrows are poorly documented in the Belle Glade culture area. Some have only been identified from old aerial photographs, and have since been destroyed by human activity. A number of the borrows were round. Some crescent-shaped borrows have also been found, usually partly wrapped around a mound. Round and crescent shaped borrows are always associated with other earthworks. Two isolated borrows are the Pestle Earthwork, shaped like the silhouette of a
pestle with a handle and a wedge-shaped head, and the Oxer Borrow, which appears to be two wide ditches forming a cross with a crescent-shaped borrow at one end of the longer ditch. Embankments are very common at sites in the Belle Glade area. Most are linear, but some are curved. They are almost always found at sites with other elements, usually connecting to such elements to form complex earthworks. At some larger sites, linear embankments connect curved embankments to mounds. While some linear embankments are not associated with other elements, curved elements always are, either connected to linear embankments or enclosing mounds.
Types Circular ditches usually have one or more mounds within the circle. Two overlapping circular ditches are enclosed in the Great Circle at Fort Center. Some circular ditches have circular borrows around the outside rim of the circle (Johnson states that these may be later additions). The West Okeechobee Circle has linear features attached to the circle (Johnson states that it may be transitional between circular ditches and circular-linear earthworks). Mounds, embankments, borrows, and ditches are combined in circular-linear earthworks. Both linear and curved embankments may be connected to mounds. Borrows surround mounds and are in contact with the rims of curved embankments. Ditches run between borrows. Johnson distinguishes two types of circular-linear earthworks. Type A, the earlier type, consisted of a curved embankment with an attached linear embankment connecting it to mound used for habitation. This form typically had a midden opposite the curved embankment. Type B had multiple linear embankments radiating like spokes of a wheel. Linear embankments are sometimes found separate from other elements at some sites, but are usually attached to a mound at one end. Linear embankments lead to the center of the two rectangular ditches. Many sites in the Belle Glade area have groups of mounds. Many of the mounds were habitation mounds, and often have a midden layer over a constructed mound. ==Sites==