Causeways - Ancient Man-Made Ritual and Functional Roads

Ancient Road Fragments Connecting People to Temples, and Crossing Bogs

Causeway to Saqqara, Egypt, during a Sandstorm
Causeway to Saqqara, Egypt, during a Sandstorm. David Degner / Getty Images

A causeway is a term used by archaeologists to refer to human-constructed functional and/or ceremonial roadways or roadway fragments. They are earthen or rock structures that typically—but not always—bridged a waterway. Causeways may have been constructed to cross defensive structures, such as moats; irrigation structures, such as canals; or natural wetlands, such as marshes or fens. They often have a ceremonial element to them and their ritual significance can include symbolic passages between the mundane and the sacred, between life and death.

Causeways are remarkably different in function. Some (like those of the classic Maya) were almost certainly used for parades for diplomatic visits between communities; others such as the 14th century Swahili coast were used as shipping lanes and ownership markers or trackways assisting navigation through uncertain landscapes (European Neolithic). Some causeways are elaborate structures, elevated several feet about the ground (Angkor civilization); others are built of planks that bridge peat bogs (Irish bronze age). But all of them are human-constructed roadways and have some foundation in the history of transportation networks.

Earliest Causeways

The earliest known causeways are Neolithic causewayed camps, constructed in Europe and dated between 3700 and 3000 BC. These causeways are part of enclosed or fortified settlements, located on chalk downs and river terraces. Most enclosed settlements have defensive elements, one or more concentric ditches with only one or two closely protected entry points.

But the ditches at causewayed camps are interrupted at several points (often from cardinal directions) by causeways permitting easy access into the interior.

Since multiple entryways would not be easily defended, such sites are considered likely to have had a ceremonial or at least a shared communal aspect.

Sarup, a Funnel Beaker causewayed camp in Denmark occupied between 3400-3200 BC, was built to enclose an area of some 8.5 hectares (21 acres), and it had several causeways piercing the ditches which closed off the landward side.

Bronze Age Causeways

Bronze Age causeways in Ireland (called tochar, dochair or togher) are trackways, built to allow access into the bogs where peat might be cut for fuel. They varied in size and substance—some were built as a line of planks laid end to end, flanked on each side by two round timbers; others were made of flat stones and gravel laid on a foundation of brushwood. The earliest of these date to about 3400 BC.

Early dynastic and Old Kingdom pyramids in Egypt often were constructed with causeways connecting the various temples. These causeways were explicitly symbolic, representing a route that people could use to travel from the Black Land (the land of the living and a place of order) to the Red Land (a place of chaos and the realm of the dead).

Beginning in the 5th dynasty, pyramids were built with an orientation following the daily course of the sun across the sky. The oldest causeway at Saqqara was paved with black basalt; by the time of Khufu's rule, causeways were roofed and the internal walls were decorated in fine relief, frescos that depicted pyramid construction, agricultural scenes, craftsmen at work and themes of battles between Egyptians and their foreign enemies, and the pharaoh in the presence of gods.

Classic Period Maya (600-900 AD)

Causeways were a particularly important form of connection in lowland areas in North America such as those settled by the Maya civilization. There, causeways (known as sacbeob, singular sacbe, connected Maya cities for distances up to 100 kilometers (63 miles).

Maya causeways were sometimes built from the bedrock up and can rise as high as 3 meters (10 feet); their widths range from 2.5 to 12 m (8-40 ft), and they connect major Maya city-states. Others are barely above ground level. Some are quite long, such as the Late Classic Yaxuna-Coba sacbe, which is 100 km long. 

Medieval Period: Angkor and the Swahili Coast

At several sites of the Angkor civilization (9th-13th centuries), elevated causeways were constructed as later additions to the immense temples by king Jayavarman VIII (1243-1395).

These causeways, elevated above the ground by a series of columns, provided walkways connecting the major buildings of the temple complexes and were only one part of the enormous Khmer road system, a network of canals, pathways and roads which kept the Angkor capitals in communication.

During the height of the Swahili coast trading communities on the east coast of Africa (13th-15th centuries AD), numerous causeways were constructed out of blocks of reef and fossil coral along 120 kilometers (75 miles) of coastline. These causeways were elevated pathways that extended out perpendicularly from the coast into lagoons at Kilwa Kisiwani Harbor, ending in circular platforms at the seaward side.

The fishermen today call them "Arab Roads", which is a reference to the oral history which credits the founding of Kilwa to the Arabs, but like Kilwa itself the causeways are known to have been African constructions, built as navigational aids for ships plying the trade route in the 14th-15th centuries and complementing the Swahili urban architecture. These causeways are built of cemented and uncemented reef coral, up to 200 m (650 ft) long, 7-12 m (23-40 ft) wide and built up above the seafloor up to .8 m (2.6 ft).

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