IF TRINIDAD and Tobago immediately conjure up Calypso, sandy beaches and flip-flops, you’re only thinking of the Tobago part. Tourist-focused and largely Afro-Caribbean, Tobago is physically and culturally distinct from the other part of the dual-island republic. Some 95% of the country’s population live southwest on Trinidad, an energy-rich, highly energetic island that’s geographically closer to Venezuela and spiritually nearer to India.

Under British rule in the 19th century, some 150,000 laborers, primarily from South...