Kihnu is an island in the Baltic Sea. With an area of 16.4 km2 (6.3 sq mi) it is the largest island in the Gulf of Riga and the seventh largest island of Estonia. The length of the island is 7 km (4.3 mi) and width 3.3 km (2.1 mi), the highest point is at 8.9 metres (29.2 ft) above sea level.