Kauai Interesting Facts - Kauai is the fourth-largest Hawaiian island. It is the least populated of the state’s four counties with roughly 62,000 residents. While the island itself is not heavily populated, according to the Hawaii Tourism Authority (HTA), the island receives nearly 1,000,000 tourists each year! On average, over 80,000 visitors come to Kauai. The island is 33 miles long and 25 miles wide.