The upper run of the Puahu River leads through the thick jungles in the southeastern part of the island. The valley remains rather inaccessible to outsiders because of prohibitive terrain and obnoxious amount of insects and venomous things inhabiting the banks and the undergrowth. On the other hand, flowers are breathtaking, with beds of orchids in the most extravagant colours awing any lover of nature into catatonic amazement. It is possible that some hot vents are in the area since warm mists shroud some swaths of treetops.