North Buena Vista is a city in Clayton County, Iowa, United States. The population was 109 at the time of the 2020 census, down from 124 i…North Buena Vista is a city in Clayton County, Iowa, United States. The population was 109 at the time of the 2020 census, down from 124 in 2000. According to the United States Census Bureau, the city has a total area of 1.04 square miles, of which 1.00 square mile is land and 0.04 square miles is water.