Diamond Head — Likely the most easily accessible hike on O'ahu, this .7-mile jaunt takes about 1.5 hours to complete (1 hour up, 1/2 hour down). The trail is paved almost the entire way, but some areas are steep.

There are two sets of stairs — 99 steps and 76 steps — and a 225-ft. unlit tunnel. At the summit, there's a breathtaking view from Waikiki to Koko Head, so don't forget your camera. Open year round from 6 a.m. to 6 p.m. Cost is $1 for walk-ins, $5 per carload.

Tips: The best time to go is before 8 a.m. and after 1 p.m. when the tour groups are not there. There is no shade, so take water, sunscreen and a hat. A flashlight comes in handy in the tunnel.

Manoa Falls — An easy one hour hike right in Honolulu takes you to one of Hawai'i's most beautiful waterfalls. At the very end of Manoa Road, just past the old Paradise Park parking lot on the right and the entrance to the now closed Lyon Arboretum is a heavily-shaded area of dead-end road, alongside of which you are permitted to park.

Tip: The parking lot and area is notorious for break-ins. To minimize being a victim, don't leave anything visible in the car.

Judd Memorial (a.k.a. Jackass Ginger) — This short valley loop goes through a thick forest of swamp mahogany, bamboo, guava and Norfolk Pine trees. On the return leg, you'll arrive at one of O'ahu's most popular swimming holes — Jackass Ginger. To get to the trailhead, take the Pali Highway to Nuuanu Pali Drive. When Poli Hiwa Place intersects to your left, you will see a small parking area (a strip of roadside shoulder for about five cars) to the right.

Tips: Giant boulders create a waterfall cascade and one of the mossy, algae-covered boulders makes for a terrific waterslide. There's even a rope swing attached to a nearby tree.

Kahana Valley State Park — This is a double-loop trail known for good swimming and camping. The second loop has some magnificent scenery. Take Likelike Highway to Kahekili Highway west. The park will be on the right.

Tips: Go during mango season (June through August). There are huge mango trees along the way, bearing lots of delicious fruit. And don't forget your mosquito repellent — there are lots of mosquitoes, too! Try this: pin a used dryer sheet (i.e. Bounce) to your shorts. Some folks say it's a sure-fire way to keep those nasty mosquitoes away.

Kaluanui Trail (a.k.a. Mariner's Ridge) — Here's a good family day activity. This hike starts off as a dusty climb, but soon enters a shady pine forest. A treat awaits you at the summit — awesome Windward views. Drive to the very top of Kaluanui Road in Mariner's Ridge and park at the end. You'll see a metal sign leading you to the trailhead on the east side of the last residence.

Tips: The trail gets busy around late afternoon on weekdays, since area residents use it as an exercise route. Because of this, parking near the trailhead may be limited then.

Makapu'u Lighthouse Road — Popular with residents and one of O'ahu's easiest hikes, this asphalt road was built to maintain the automated Makapuu Lighthouse. It is a vantage point for stunning Windward coastal views and whale watching. The paved road is 1.4-miles long (one-way). A dirt path on the west end continues where the paved road leaves off. It reaches the highest point of Makapu'u Point off to the right side.

Tips: The start of Makapuu Lighthouse Road begins at a locked, vehicular gate along Kalanianaole Highway (Hwy 72). Proceed through the gate and stay on the road. Get your business done before arriving.

Parking is scarce and there are no restroom facilities. Parking near the trailhead is available along the public highway — be careful of the passing traffic.

Kuli'ou'ou Ridge Trail — If you're looking for great scenery while getting a good workout, this 1,700-foot-climb and 3.4-mile hike fulfills both needs. The windswept summit with coastal views of white-sand Waimanalo and Lanikai Beaches, deep green forests, and the shimmering sea make the effort entirely worthwhile. The trailhead is at the end of Kalaau Place. Look for the signs.