An Endless Horizon of Sand and Atlantic Swells
Stretching from the western breakwater of the Rio Grande estuary in southern Brazil all the way down to the mouth of the Chuí Stream at the Uruguayan frontier, Praia do Cassino (Casino Beach) spans a continuous, unbroken length of approximately 254 kilometers (158 miles).
Recognized officially by the Guinness Book of World Records as the longest uninterrupted sea beach on Earth, the shoreline is an extraordinary expanse of hard-packed silica sand, vast parabolic coastal dunes, and dramatic maritime history.
Geological Formation: The Holocene Barrier System
The origin of Praia do Cassino's staggering length lies in the unique coastal dynamics of the Rio Grande do Sul coastal plain. Over millions of years, the convergence of the southward Brazil Current and the northward Falkland/Malvinas Current deposited hundreds of millions of cubic meters of fine sediments along the Atlantic margin.
Unlike rocky coastlines punctuated by cliffs, headlands, or fjords, this section of South America formed as an uninterrupted sand barrier lagoon system (Barrier-Lagoon IV), separating the massive freshwater lake Lagoa dos Patos and Lagoa Mirim from the open Atlantic Ocean.
The Cassino Ultramarathon: Because the sand is dense and flat enough to support vehicular traffic and long-distance runners, the beach hosts the Extremo Sul Ultramarathon, where competitors run the full 226 km to 250 km self-supported along the ocean edge.
Historic Shipwrecks: The Altair Landmark
Navigating this coastline during the 19th and early 20th centuries proved treacherous due to frequent winter pampero storms and featureless topography. Located approximately 16 kilometers south of the Cassino urban center lies the iron skeleton of the Altair, a cargo ship that ran aground in June 1976 during a violent hurricane-force gale. Over decades, the rusting hull has transformed into a thriving artificial micro-reef and landmark for coastal travelers.
The World's Longest Beaches: Verified Ranking
| Beach Name | Continuous Length | Country | Key Characteristic |
|---|---|---|---|
| Praia do Cassino | 254 km (158 mi) | Brazil | Longest continuous ocean beach on Earth |
| Cox's Bazar Beach | 120 km (75 mi) | Bangladesh | Longest natural unbroken sandy sea beach in Asia |
| Padre Island Seashore | 113 km (70 mi) | USA (Texas) | Longest undeveloped barrier island beach |
| Ninety Mile Beach | 88 km (55 mi) | Australia (Victoria) | Pristine uninterrupted ocean sand spit |
| Ninety Mile Beach | 88 km (55 mi) | New Zealand | Official designated highway along the sand |