Lake Maracaibo is a large brackish tidal bay in Venezuela and an "inlet of the Caribbean Sea. It is sometimes considered a lake rather than a bay or lagoon. It is connected to the Gulf of Venezuela by Tablazo Strait which is 5.5 kilometres (3.4 mi) wide at the northern end. It is fed by numerous rivers, the largest being the Catatumbo. At 13,210 square kilometres (5,100 sq mi) it was once the largest lake in South America; the geological record shows that it has been a true lake in the past, and as such is one of the oldest lakes on Earth at 20–36 million years old.

Lake Maracaibo acts as a major shipping route to the ports of Maracaibo and Cabimas. The surrounding Maracaibo Basin contains large reserves of crude oil, making the lake a major profit center for Venezuela. The basin also holds almost a quarter of Venezuela's population. A dredged channel gives oceangoing vessels access to the bay. The 8.7-kilometre (5.4 mi) long General Rafael Urdaneta Bridge, which was completed in 1962 and spans the bay's outlet, is one of the longest bridges in the world.

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