Kauai, Hawaii's fourth largest island, is known as the "Garden Isle" due to its lush, tropical landscape of emerald valleys, jagged cliffs, and rainforests dotted with waterfalls. The circular island has rugged, mountainous regions in its center and beaches covering almost half its shoreline. Key attractions highlighted in the document include the dramatic Waimea Canyon, beautiful Napali Coast, small towns of Hanalei and Lihue, and various botanical gardens, beaches, hiking trails, and cultural sites throughout the island.