Port of Spain (/ˌpɔːrt əv ˈspeɪn/ PORT əv SPAYN; Trinidadian English: Port ah Spain is the capital and chief port of Trinidad and Tobago.Wit…Port of Spain (/ˌpɔːrt əv ˈspeɪn/ PORT əv SPAYN; Trinidadian English: Port ah Spain is the capital and chief port of Trinidad and Tobago.With a municipal population of 49,867, an urban population of 81,142 and a transient daily population of 250,000, it is Trinidad and Tobago's third largest municipality, after Chaguanas and San Fernando.