Dimond Head Hikes
The iconic Diamond Head State Park offers hikes, scenic views, as well as military history. The park is over 475 acres wide, including slopes of this huge crater. This crater was formed by a volcanic eruption over 300,000 years ago.
The park times are 6:00am to 6:00pm, and the last hike entrance is at 4:30pm. For more information, go to the official Hawaii State Parks website.
Pearl Harbor Memorial
This historic place led to America joining one of the largest wars in Earth's history. Pearl harbor, as well as being a historic national landmark, functions as an active military base 
and headquarters for the Pacific Fleet.
See battleships from WWII, including the USS Missouri Memorial, USS Arizona, USS Bowfinn Submarine Museum, and the Pacific Aviation Museum. Prices for each attraction range from $7.50 to $27.00. For more information, visit the official Pearl Harbor visitor website.
North Shore
The famed North Shore is the premier place for surfing in Oahu. The 7-mile stretch of coast boasts several surfing competitions during the winter months. These waves can reach up to 30 feet, so be careful and leave surfing to the pros.
But during the summer months, tranquility returns, and North Shore becomes a place of casual surfing, swimming, and sunbathing. For more information, click here.