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Hiking Mount Lamlam in Guam, the Tallest Mountain in the World

Hiking Mount Lamlam, Guam, USA

Hiking Mount Lamlam, Guam, USA

Mt Lamlam - The World's Tallest Mountain

I hiked the world's tallest mountain one morning. I had some snacks at the summit and met a cute wild dog on the descent.

No, I am not making this up, nor have I got crazy. Technically speaking, Mt. Lamlam in Guam is the world's highest mountain and, in my opinion, no visit to Guam is complete without taking a trip up! With an easy to find trail and beautiful views, the Mt. Lamlam hike is easy enough to accomplish in a couple of hours.

Lamlam, also written Lam Lam or LamLam, is 1,332 ft above sea level at its highest point, but, since it rises from the Mariana Trench, it is technically the highest mountain on Earth. It isn't the highest mountain above water, but if you dropped Everest in the Mariana Trench, there would be about 6,000 feet of sea water above its peak! Lamlam's rise from the ocean floor marks the world's greatest change in elevation over such a short distance.

What to Bring to Hike Lamlam

The Mt. Lamlam hike is not particularly treacherous or strenuous, but there are a few things you should bring along.

  • Water. Lots of water. Lamlam is windy, which means you can get dehydrated even more quickly than on a regular hike.
  • Sunscreen. Guam is located at 13 degrees North latitude. This means the sunlight is very direct and you can burn easily, so make sure to wear plenty of high SPF sun block. You can get burned on a cloudy day, so make sure not to skimp on the sunscreen if it's overcast!
  • A camera. You won't want to miss the views!
  • Pants. If you want to take the more overgrown trail all the way to the summit, wear pants to avoid cutting yourself on the native Guamanian grass.
  • Snacks. This isn't really a must, but you may want a quick bite at the summit.

The Guam tourist map is invaluable and has everything on it. Cell phones from the continental US tend not to work on Guam, so having a physical map is important!

Directions to Mount Lamlam

Finding Lamlam is pretty easy, especially by Guam standards. Local Catholics do a Stations of the Cross up the mountain each Easter weekend and bring large crosses to the secondary peak, so most of the trail is well-worn and easy to spot. This annual event is highly anticipated and very popular because 98% of Guam's population is Catholic! Lamlam is located near the village of Agat in the southwestern portion of the island.

To reach Lamlam from the Tumon area, take Route 1 South until you have to veer left onto 2A to avoid entering the Navy base. Continue on 2 towards Agat. Drive through Agat and continue approximately 3 more miles. If you get to Ulmatec, you've gone too far and should turn around. The trailhead is on the land side of the road, but you want to park on the 'right,' if you're arriving from Agat. There are a lot of overlooks on the island, but this particular overlook has a large, distinctive wall. It is the Cetti Bay overlook and also has a trailhead that leads down to the bay, so you may notice signs for it before you see the small, green sign on the left marking Lamlam. Just check out the picture below to see what I mean!

The approach to the Cetti Bay overlook, as seen coming from Agat.

The approach to the Cetti Bay overlook, as seen coming from Agat.

Cetti Bay overlook in Guam

Cetti Bay overlook in Guam

Hiking Mount Lamlam

Across from the parking lot, you will see a small sign for Lamlam. The trail is fairly worn since it is well traveled by local Catholics each spring -you can see the large wooden crosses on the mountain's secondary peak during your entire hike.

Lamlam sign

Lamlam sign

Even though the trail is easy to follow, the rainy season downpours create some fierce erosion!

The trail is pretty steep in places!

The trail is pretty steep in places!

As you hike, you will notice crosses. When I showed her photos, my sister's first response was "Man, how many people have died here!" Don't worry - they're not that kind of cross. They are from the Stations of the Cross conducted by local Catholics.


Part way up the mountain, you will see a shrine to the Virgin Mary. It's pretty cool looking, and obviously used frequently.


A short distance away from this shrine, you can choose to either continue walking to your right, up the worn trail towards the crosses, or bushwhack your way to the mountain's peak. This divergence happens behind cross XI, shown below.

Cross XI, where the paths split.

Cross XI, where the paths split.

To the Summit

The left hand trail is a bit more like a Guam trail than the 'main' trail. By that I mean it's sort of marked and mostly overgrown. Actually, there are pretty consistent plastic tape markings all the way to the summit.


The trail is very narrow, so I highly recommend wearing pants if you don't want the grass to cut you!

The narrow trail to the summit.

The narrow trail to the summit.

Just keep following the pink tape all the way to the summit. Once you reach the peak, you'll be rewarded with beautiful, 360 degree views of the entire island. My pictures really don't to it justice - it was overcast and trying to rain when I was at the summit and my photos are, consequently, less than poster-worthy.

Cetti Bay

Cetti Bay


To the Crosses

If you follow the main path to the right, instead of bushwhacking past cross XI, you will have a much easier time of things and equally pretty views. I walked the left trail and then the right trail for the full experience! The crosses have a commanding view of Cetti Bay.

Lamlam crosses

Lamlam crosses

Mount Lamlam Hike

And there you have it! A complete guide to hiking Mount Lamlam in Guam, USA. If you visit Guam and want to say you've hiked the world's highest mountain, but aren't sure about your hiking skills, you can always take a guided trip with the Boonie Stompers. They offer experienced, professional hikes every Saturday!

Whether you choose to hike alone or with a group, a trip to Mount Lamlam is a must while you're on Guam. If you have any questions about how to locate the trailhead or what to expect, please feel free to leave your question in the comments and I'll do my best to help out!


hoteagle on October 14, 2018:

Mount Everest is the tallest mountain in the world to be TECHNICALLY correct. I have never came across an island distance chart from the Marians trench or the deepest part of the ocean "challenger deep" to make them the tallest mountain in the world. Mount Everest's deepest part is still...you guessed it...the Marians Trench. Also, if you want to play your technically game, look up Fais Island.

DBA Mountaineer on February 05, 2017:

Hi, just like to ask since I plan to visit Guam and interested to do this hike, is there cheapest transportation to Mount Lam Lam?

Natasha (author) from Hawaii on March 18, 2015:

Fair enough. I've gone left and right! I do mention the fork, but I guess I don't specify which is technically which once you make the branch.

Jeff on March 10, 2015:

That is actually Mount Jumullong Manglo. The trail splits to the right and left. On the right, the trail takes you to Mount Jumullong Manglo and the crosses, to the left takes you to Mount LamLam which is a longer hike.

Natasha (author) from Hawaii on October 17, 2013:

Oh, wow! That's cool. I love it when things I enjoyed in the past are still available.

Poohjo on October 17, 2013:

I climbed Mt.Lamlam too! I lived on Guam from 1974-1978 and graduated from high school there. I loved it!

Natasha (author) from Hawaii on June 17, 2013:

I hadn't heard of it, either! Guam is...interesting. Very pretty, but very different from what I expected, is probably the best way to put it. If you like diving or snorkeling, it has the best coral I've ever seen.

ElleBee on June 17, 2013:

Very cool! I had never heard of Lamlam before, the pictures certainly make it look like a lovely place. If I ever get to Guam....

Natasha (author) from Hawaii on May 31, 2013:

Awesome! I hope you have fun and I'm glad you enjoyed the photos! I went alone and didn't have any problems.

Daren on May 31, 2013:

Thanks for the detailed information on the hike. Your photos are awesome as well. I will solo climb the mountain tomorrow rain or shine and will let you know how it went. :)

Natasha (author) from Hawaii on May 21, 2013:

Thanks! It's not so super far away for you - maybe you'll be able to visit some day!

agusfanani from Indonesia on May 20, 2013:

It's a very interesting story about your exciting journey to Lamlam mountain. The beautiful pictures make it even more special!

Natasha (author) from Hawaii on May 15, 2013:

I made the hike alone so I wanted to share the experience with someone. What better place than here? Thanks for stopping by to take a look!

Rose Clearfield from Milwaukee, Wisconsin on May 15, 2013:

What a gorgeous location! Thanks for sharing your story with us.

Natasha (author) from Hawaii on May 15, 2013:

Mwahaha - my plan worked! =)

I was pretty surprised the first time I saw the claim, too. If you ever make it to Japan, Guam isn't much further. Thanks for stopping by and for the votes!

Peggy Woods from Houston, Texas on May 15, 2013:

Hi Natasha,

Your title did catch my eye and I thought to myself...Guam...no way! After reading this and comparing mountain sizes if they were all lined up in the Mariana Trench, it is interesting that Mount Lamlam would be the tallest. So...your title worked! Ha! Thanks for detailing your hike in photos and descriptions. Would be fun to do sometime. Up and interesting votes.

Natasha (author) from Hawaii on May 15, 2013:

It is kind of cool feeling to say! Thanks for stopping in =)

Claudia Mitchell on May 15, 2013:

Very cool and love that you can say that you've hiked the highest mountain in the world. Great travel hub.

Natasha (author) from Hawaii on May 15, 2013:

Thank you! I think you may be closer than my actual home, but it's still pretty far!

Rajan Singh Jolly from From Mumbai, presently in Jalandhar, INDIA. on May 14, 2013:

What a beautiful trail. I'd love to have a go but I'm so far away. Arresting pictures and excellent recounting of your hike, Natasha!

Voted up.

Natasha (author) from Hawaii on May 14, 2013:

Bdehiulio - I didnt' know, either, until I was reading up on Guam!

Hawaiianodysseus - Sadly, there are both mosquitoes and ticks on Guam. Lamlam is the only place I actually got bitten by mosquitoes on the island, but they only come out when the wind dies down, or when you're in a sheltered area. I never got any ticks in all my adventures and, apparently, the ticks there plague dogs and tend to leave humans alone. I guess their pretty species-specific!

I was hoping the title would catch some attention =)

Thanks for stopping by!

Hawaiian Odysseus from Southeast Washington state on May 14, 2013:

This Hub's title caught my eye, and I was getting ready to challenge that claim, my friend. But when I read your explanation, I thought, "You know, that makes absolutely perfect sense!"

A practical question, Natasha--were there mosquitoes up there on the mountain? Also, can one pick up ticks while walking through the tall grass?

Thanks for sharing! Aloha and blessings, my friend!


Bill De Giulio from Massachusetts on May 14, 2013:

Yes indeed, how interesting. I had no idea. What a great find. Really enjoyed this Natasha.

Natasha (author) from Hawaii on May 14, 2013:

Yes, it's an amusing technicality!

Thanks for being the first to stop by, as always =)

Bill Holland from Olympia, WA on May 14, 2013:

Well that was interesting. I had no idea it was the tallest mountain in the world. Great hub for tourists everywhere....very nice job of detailing the trip.