I would like to add to the above. I will never forget the Terra-cotta warriors in Xian China and Machu-Picchu in Peru.

Walking down Blvd. de L'Hopital and catching my first glimpse of Notre Dame from the back. It was just like the pictures only it was real.

Hi I'm new here. What a delightful site this is and such an intriguing question.
Aside from the moments and places filled with natural beauty that always fills me with wonder, there have been a couple of man made instances.
The first, was in the Peggy Guggenhiem Collection in Venice. The painting by Rene Magritte, Empire of Light, took my breath away, dropped my jaw and made me sit down and appreciate. This has for many years been my one of my favorite paintings and to see it live and large opened up a new horizon of understanding.
The second was a man made horror. I have only read about the holocaust and faintly realized the number of lives lost to that mass hatred. The Jewish Temple in Prague where the names of the Holocaust victims are painted on the walls dropped my jaw. When I walked through room after room and began to really see how drops of fear, hatred and judgement can turn into a deluge of horror. I think this has made me think more about petty judgements and be more loving towards my fellow people.
Well, for one of my first post on a site, perhaps I should have chosen something like, grand canyon or monseratte but here it is. Thanks for asking, thanks for sharing.

Great thread:
1) Driving from Denver, CO, with the Rockie's looming, and then you are IN THEM...Also, standing atop a mountain in Vail and the snow-capped mountains were all around, everywhere the eye could see;
2) Standing on the shore of Lake Ontario in Oswego, NY, watching the
(sp?) Aurora Borealis change the colors of the night sky
3) Looking out from the observation tower of the World Trade Center....and watching those buildings come down so many years later

Thank you for this site and so many things to plan to see in my lifetime!

Hello, I love reading everyone's comments on this thread! Here's what were jaw dropping sites for me:

The entire city of Prague...absolutely beautiful wherever you turn. Especially the Charles Bridge, Castle, and Petrin Hill lit up at night.

The interior of St. Mary's Church in the Main Square of Krakow. I knew nothing about this church before I went inside and my jaw dropped at the beautiful, ornate architecture. The most ornate church I've seen! Definitely a must.

Auschwitz-Birkenau - very depressing and sombering but a must. I know that many people I know don't realize what the daily life of the prisoners were like...I think a visit here is an important history lesson.

Cape Sounion and Adelphi in Greece.

Trunk Bay, Cinnamon Bay and Caneel Bay on St. John in the Virgin Islands.

The Great Wall of China, the Forbidden City (beautiful, huge and spectacular) and the limestone Karst formations along the Li River in Guilin, China.

Also forgot to add the view from the top of Victoria Peak in Hong Kong at night. Breathtaking!

Seeing El Castillo and the large cenote at Chichen-Itza. Amazing

What a great question!

Some of mine would be:

Lecce's Santa Croce: the church is Lecce-style baroque and is simply filled with as many decorations and ornate designs as possible. It was completely jaw-dropping.

The Frasassi Caves in Genga, Italy--its first room on the tourable part was enormous and filled with beautiful stalagtites and stalagmites. Definitely worth a visit if you have never been.

The view over Spain from the airplane when arriving--what amazing colors and vast spaces!

Driving through Le Marche mountains (that road through the Valnerina from Le Marche into Umbria is fantastic)!

Seeing the Eiffel Tower for the first time.

And perhaps most importantly...
My little town of Macerata when I arrived the first day 5 years ago: it was Italy. I was finally there.

- Victoria Falls, Zimbabwe. Brings tears to your eyes.Hope to be able to return someday.
- I was stunned at Prague's beauty and will definitely be returning.

1) Prague lit at night
2) the remaining bits of the Berlin Wall
3) the fjords
4) the drinks bills in Norway

The Island of Santorini is incredible and I have never seen a prettier blue than the Agean Sea.

The Pont du Gard, in the South of France. Chartres Cathedral rising up from the surrounding plain. The interior of Wells Cathedral in England. Stonehenge on a moonlit night.

Michelangelo's Pieta. First time I saw it was at the New York World's Fair and the next was at the Vatican in Rome. Both times it's beauty brought me to tears.

The view of the Amalfi coast from the gardens of the Villa San Michele in Anacapri.
Walking along the riverside towards the Vatican for the first time.
My first view of the Grand Canyon made me cry.

Also, going over the bridge for the first time towards Manhattan at night, seeing the sheer enormity of it all, lit up, World Trade Center still standing, and realising just how small and insignificant I am

I just stumbled on this thread. How fortunate we are to be able to see and appreciate so many of this world's special places. I am amazed at how many of these places that I have visited.One previous writer mentioned southern Utah, Zion National Park was one place my wife and I loved. Muir Woods, north of San Francisco another.Vesuvius as a young Navy type,the Parthenon likewise.Italy is acolumn of its own. Any waterfall, anywhere or any of the underground caverns and hopefully more to add at a later date. ...Did I mention Park Guell?

Wow! I am lucky to have seen several of the before mentioned jaw dropping sites (Eiffel tower, Sistine Chapel, Venice,Matterhorn, Peggy's Cove, PEI and the fields of lupins). A few more:
-driving in the Swiss Alps and not being able to see how far below was! The incredible views and the wonderment of how people live on the edge of a mountain!
-Walking by a cafe one afternoon in Paris and hearing the most beautiful version of Ava Maria. Looked in to see that it was the bar lady singing!
-Going to Mauthausen Austria and the concentration camp there in that incredibly pastorial and picturesque setting. We could not speak.
-The sunsets viewed from our cottage on the Northumberland Straight from the Nova scotia side.
-The aftermath of Hurricane Juan. Luckily not as severe a hurricane as others have experienced-but a week with out power and all the huge up-rooted trees! My jaw still drops as I continue to see giant tree roots sticking out of the ground.

The Northern lights, seen from a ship in Alaska. The colors just kept changing and moving around! Also Iquazzu Falls, especially the Devil`s throat. It wasn`t just seeing it, it was hearing it too.

After our most recent trip to northern Italy, I need to add Milan's Duomo...inside and out.

Right off the top of my head... Lake Louise in Banff, Canada. This was gosh, ages ago but when my car turned into full view of the lake, everyone in the car just went WOW!! Jaw dropping, time stood still and all.

It was like a painting. Couldn't believe it was real.