The Greater Antilles is a group of large islands in the Caribbean Sea that includes Cuba, Hispaniola (shared by Haiti and the Dominican Republic), Jamaica, and Puerto Rico. Together, these islands cover about 207,435 square kilometers, making up the vast majority of the Caribbean’s total land area. They stretch eastward from Mexico’s Yucatan Peninsula and form a natural barrier between the Caribbean Sea and the Gulf of Mexico.
The Islands and Their Scale
The Greater Antilles dwarfs the rest of the Caribbean in size. The Lesser Antilles, the long chain of smaller islands curving south toward South America, totals only about 13,000 square kilometers. That means the Greater Antilles accounts for roughly 94% of the Antillean land mass. Cuba alone is the largest Caribbean island, followed by Hispaniola, Jamaica, and Puerto Rico.
These are mountainous islands, not flat coral atolls. Pico Duarte in the Dominican Republic rises to 3,098 meters (10,164 feet), making it the highest point in the entire Caribbean. Jamaica’s Blue Mountain Peak reaches 2,256 meters (7,402 feet). This rugged terrain creates dramatic differences in rainfall and vegetation from one side of an island to the other, with lush rainforests on windward slopes and drier conditions in the rain shadows.
Population and Nations
More than 30 million people live across the Greater Antilles. Haiti, the Dominican Republic, and Cuba each have populations exceeding 10 million, placing them among the most populous island nations in the world. Puerto Rico, a U.S. territory, has roughly 3.2 million residents. Jamaica rounds out the group with about 2.8 million. The region’s cultural fabric is layered, shaped by Indigenous Taíno heritage, centuries of Spanish, French, and British colonialism, the African diaspora, and waves of migration that continue today.
How the Islands Formed
The Greater Antilles owes its existence to the collision and interaction of tectonic plates over tens of millions of years. The Caribbean plate sits between the North American and South American plates, and its boundaries feature opposing subduction zones where ocean floor dives beneath adjacent plates. Between roughly 66 and 23 million years ago, the region underwent a major tectonic reorganization. An older subduction system called the Great Arc of the Caribbean gradually shifted into a transform boundary (where plates slide past each other), while a new subduction zone formed to the east, eventually building the Lesser Antilles volcanic arc.
This complex plate activity pushed up the mountain ranges that define the Greater Antilles today. Unlike the smaller volcanic islands to the south, the Greater Antilles are composed of a mix of volcanic, metamorphic, and sedimentary rocks, reflecting their long and complicated geological history.
Wildlife Found Nowhere Else
The Greater Antilles is a biodiversity hotspot with an extraordinary number of species found nowhere else on Earth. Because the islands have been separated from the mainland for millions of years, animals and plants that arrived from South America between roughly 45 and 25 million years ago evolved in isolation. That ancient colonization brought the ancestors of today’s Caribbean tree frogs, iguanas, geckos, blind snakes, worm lizards, and freshwater fish. The islands were once home to now-extinct primates and giant sloths.
As tectonic forces slowly separated what was once a larger connected landmass into distinct islands, populations became isolated from each other. This triggered waves of speciation, producing species unique to a single island. Puerto Rico, for example, has numerous single-island endemic reptiles and amphibians. Cuba’s solenodons, small insectivorous mammals that resemble shrews, are among the most ancient and unusual surviving land mammals in the Caribbean.
Coral Reefs Under Pressure
The waters surrounding the Greater Antilles host 63 species of reef-building corals, more than any other ecoregion in the Atlantic. The wider Caribbean accounts for about 10% of global reef coverage and has historically served as a source for coral species dispersal throughout the Atlantic.
These reefs have been under severe stress for decades. Steep declines began in the 1970s and 1980s when diseases devastated the structurally important elkhorn and staghorn corals and nearly wiped out the long-spined sea urchin, a key herbivore that kept algae from smothering reef surfaces. Since 2014, Stony Coral Tissue Loss Disease (SCTLD) has spread through the region and is now considered the most damaging coral epidemic in decades. It disproportionately kills the coral species that provide three-dimensional reef structure, shifting reefs toward simpler, slower-growing species and increasing algae dominance.
There is a silver lining in the data: the Greater Antilles ecoregion has actually seen an average 34% increase in coral cover over the past 30 years, likely reflecting recovery in some areas even as others decline. But regional climate projections suggest ocean temperatures will reach levels that trigger annual severe bleaching by around 2030, putting that recovery at risk.
Hurricanes and Climate Exposure
The Greater Antilles sits squarely in the Atlantic hurricane belt. An average Atlantic hurricane season produces 14 named storms, 7 hurricanes, and 3 major hurricanes of Category 3 or higher. The islands’ position means they frequently take direct hits or experience close passes from these storms. Cuba’s western tip lies just 150 kilometers from the Yucatan, and the entire chain forms a wall that intercepts storms tracking westward or curving northward through the Caribbean.
The mountainous terrain amplifies rainfall totals during hurricanes, triggering landslides and flash flooding that can be as destructive as the wind itself. Haiti, with extensive deforestation and limited infrastructure, is particularly vulnerable to these cascading effects.
Tropical Disease Risks
The warm, humid climate across the Greater Antilles creates ideal conditions for mosquito-borne diseases. Dengue is endemic in Puerto Rico, which reported nearly 30,000 cases between 2010 and 2020, with children and adolescents disproportionately affected. Annual incidence peaked at about 2.9 cases per 1,000 people during outbreak years. Zika virus emerged in the region in 2016, temporarily suppressing dengue transmission as the same mosquito species carried both viruses. Malaria has been largely eliminated from most of the Greater Antilles, though Hispaniola remains the last Caribbean island where it still circulates, primarily in Haiti.