Makapuʻu Point Lighthouse is a 46-foot tall, active United States Coast Guard lighthouse established in 1909. Construction for the lighthouse was prompted by the grounding of the steamer Manchuria in the predawn hours on August 20, 1906 on the reefs off Waimânalo. The lighthouse was automated in 1974 and its keepers quarters demolished in 1987, but the remnants are still visible. The lighthouse contains a roughly 12-foot tall French Fresnel hyper-radial lens, the largest lens in use in the United States. The lens is able to magnify and intensify the illumination of a single electrical 1,000-watt, 120-volt light bulb. It was damaged by a vandal firing a bullet at it, but the lens is still in service as it is no longer reproducible. A popular day hike along the access road to the lighthouse begins at a parking lot located south of the Makapuʻu lookout on Kalanianaole Highway. A second trail leads from the remnants of the keepers quarters to the lighthouse, but it is off limits to the public. The lighthouse itself is also off limits to the public and is protected by three locked gates.