Trinidad, officially La Santísima Trinidad, is a city in Bolivia, capital of the department of Beni. The population is 130,000. While historically a p…Trinidad, officially La Santísima Trinidad, is a city in Bolivia, capital of the department of Beni. The population is 130,000. While historically a peripheral city in Bolivia, Trinidad is today an important center for the Bolivian Bovine industry and has enjoyed a modest economic boom in recent years and has an HDI index of above 0.700.