Manra, or Sydney Island, measures approximately 3. 2 by 2. 8 km (2. 0 by 1. 7 mi), with a large, salty lagoon with depths reportedly varying from five to six meters. The island is covered with coconut palms, scrub forest, herbs and grasses, including the species Tournefortia, Pisonia, Morinda, Cordia, Guettarda, and Scaevola. Manra contains definite evidence of prehistoric inhabitation, in the form of at least a dozen platforms and remains of enclosures in the northeast and northwest portions of the island. K. P. Emory, ethnologist at Honolulu's Bishop Museum, estimated that two groups of people were present on Manra, one from eastern Polynesia, the other from Micronesia. Wells and pits from these early inhabitants were also found.