Nuʻuanu Pali is a section of the windward cliff of the Koʻolau mountain located at the head of Nuʻuanu Valley on the island of Oʻahu. It has a panoramic view of the windward (northeast) coast of Oʻahu. The Pali Highway (Hawaii State Highway 61) connecting Kailua/Kāneʻohe with downtown Honolulu runs through the Nuʻuanu Pali Tunnels bored into the cliffside.
The area is also the location of the Nuʻuanu Freshwater Fish Refuge and the Nuʻuanu Reservoir in the jurisdiction of the Hawaiʻi Department of Land and Natural Resources.
The Nuuanu Pali State Wayside is a lookout above the tunnels where there is a panoramic view of the Oʻahu’s windward side with views of Kāneʻohe, Kāneʻohe Bay, and Kailua. It is also well known for strong trade winds that blow through the pass (now bypassed by the Nuʻuanu Pali Tunnels). The The Tunnels were built in 1958. Before this road opened, people would use the what is now known as the Old Pali Road. The Old Pali Route is now a popular hiking route
Source : wikipedia