Trinidad and Tobago is an archipelagic republic in the southern Caribbeanbetween the Caribbean Sea and the North Atlantic Ocean, northeast ofVenezuela. They are southeasterly islands of the Lesser Antilles, located close to the South American mainland.
Covering an area of 5,128 square kilometers (1,980 sq mi), the country consists of the two main islands, Trinidad and Tobago, and numerous smaller landforms – including Chacachacare, Monos, Huevos, Gaspar Grande (or Gasparee), Little Tobago, and St. Giles Island. Trinidad is 11 km (6.8 mi) off the northeast coast of Venezuela and 130 km (81 mi) south of the Grenadines. The island measures 4,768 km2 (1,841 sq mi) in area (comprising 93.0% of the country's total area) with an average length of 80 km (50 mi) and an average width of 59 km (37 mi). The island appears rectangular in shape with three projecting peninsular corners. Tobago is 30 km (19 mi) northeast of Trinidad and measures about 298 km2 (115 sq mi) in area, or 5.8% of the country's area, 41 km (25.5 mi) in length and 12 km (7.5 mi) at its greatest width. The island is cigar-shaped in appearance, with a northeast-southwest alignment.
Geologically, the islands are not part of the Antillean arc. Rather, Trinidad was once part of the South American mainland and is situated on itscontinental shelf, and Tobago is part of a sunken island arc chain related to the Pacific-derived Caribbean Plate. The islands are separated from the continent of South America by the Gulf of Paria; Dragon's Mouth, a 19-kilometer (11.8 mi)-wide northern passage; and Serpent's Mouth, a 14-kilometer (8.7 mi)-wide southern passage.
Trinidad is traversed by three distinct mountain ranges that are a continuation of the Venezuelan coastal cordillera. The Northern Range, an outlier of the Andes Mountains of Venezuela, consists of rugged hills that parallel the coast. This range rises into two peaks. The highest, El Cerro del Aripo, is 940 meters (3,084 ft) high; the other, El Tucuche, reaches 936 meters. The Central Range extends diagonally across the island and is a low-lying range with swampy areas rising to rolling hills; its maximum elevation is 325 meters (1,066 ft). The Caroni Plain, composed of alluvial sediment, extends southward, separating the Northern Range and Central Range. The Southern Range consists of a broken line of hills with a maximum elevation of 305 meters (1,001 ft).
There are numerous rivers and streams on the island of Trinidad; the most significant are the Ortoire River, 50 kilometers (31.1 mi) long, which extends eastward into the Atlantic, and the 40-kilometer (24.9 mi)-long Caroni River, reaching westward into the Gulf of Paria. Most of the soils of Trinidad are fertile, with the exception of the sandy and unstable terrain found in the southern part of the island.
Tobago is mountainous and dominated by the Main Ridge, which is 29 kilometers (18 mi) long with elevations up to 640 meters. There are deep, fertile valleys running north and south of the Main Ridge. The southwestern tip of the island has a coral platform. Although Tobago is volcanic in origin, there are no active volcanoes. Forestation covers 43 % of the island. There are numerous rivers and streams, but flooding and erosion are less severe than in Trinidad. The coastline is indented with numerous bays, beaches, and narrow coastal plains.