The marina is located on the intercoastal waterway between Dunedin Causeway and Clearwater Causeways. Typical earthworks include road construction, railway beds, causeways, dams, levees, canals, and berms. Natural ponds were augmented with sluices and causeways. Seawalls, causeways and a short railway were built across the swampy tidal flats. This includes the Uists themselves and the islands linked to them by causeways and bridges. This 22-acre urban park is connected to the mainland by both pedestrian and vehicular causeways. The buildings were connected by a dense network of paved causeways, called "sacbeob". The Germans were overwhelmed by the men and material that poured ashore over pontoon causeways. The last two of these are connected to the main island by permanent roads/causeways. Some low causeways across shore waters become inaccessible when covered at high tide. Most of the roads and causeways there were built during World War II. Evacuation of the Keys depends on causeways and the two-lane highway to the mainland. The Aztecs were cut off from the mainland because of the occupied causeways. Pre-Hispanic Xochimilco was an island connected to the mainland by three causeways. Many were tasked with the handling, launching, assembly, installation of pontoon causeways.