During World War II, the U.S. military built concrete bunkers all over the island of Oahu as defensive lookout posts guarding Hawaii, and most of them have amazing views of the coastline.

These ‘pillboxes’ have been abandoned ever since the war, but they’ve turned into beloved hiking destinations because of the great scenery and history behind them.

Here’s my guide for all of the pillbox hikes in Oahu, including some hidden gems!

1. Lanikai / Kailua Pillboxes

The most popular pillbox hike in Oahu is definitely the one in Lanikai, near Kailua.

If I had to choose one hike on this list as my favorite, it would be this one. This hike is short, easy, and incredibly beautiful. I can’t imagine a nicer view for a wartime bunker!

The only downside is that it’s getting pretty famous and sometimes the trail is crowded.

It’s a fun place to chill after hiking, and there’s a nice ocean breeze so it doesn’t feel too hot up there even in the middle of the day.

From the first pillbox at Lanikai, it’s only a 10 minute walk to reach the second pillbox, which is bigger.

The second pillbox actually has two separate rooms, and you can go inside either of them by climbing down a set of metal rungs.

The interiors are filled with graffiti, and looking out the windows gives another neat perspective of the outside scenery.

Just be careful with small kids near the hatch, because it wouldn’t be a good place to fall.

A safer, easier way for kids to enjoy the inside of the Lanikai pillboxes is by climbing through the front window instead, although they still may need a hand.

Distance: 1 mile (1.6 km) roundtrip
Elevation Gain: 450 feet (140 m)
Difficulty: Easy

2. Maili / Pink Pillbox Hike

It’s not a very hard hike, but the ridge is a bit steep and there’s no shade on the trail, so it can get pretty hot if you go in the middle of the day.

This hike isn’t as crowded as the one at Lanikai, and it’s a good place to watch the sunset if you don’t mind going down when it’s dusk.

Sometimes if you’re lucky, you can even see whales jumping in the distance.

Distance: 1.2 miles (2 km) roundtrip
Elevation Gain: 500 feet (150 m)
Difficulty: Easy / Moderate