Tena is a city in the Amazon rainforest of Ecuador. It is the seat of Tena Canton, as well as the capital and largest city of Napo Province. Ten…Tena is a city in the Amazon rainforest of Ecuador. It is the seat of Tena Canton, as well as the capital and largest city of Napo Province. Tena is located approximately 195 kilometers from Quito, the capital of Ecuador.