Not Europe but my jaw droppers are the Jaipur/Udaipur palaces and the TajMahal in moonlight! What a sight.

I'd also add Peuget Sound from several angles

Seeing the houses stacked up on the very steep hill in Ragusa, Sicily. Looks like a vertical wall of white and brown.

The decoration inside the Alcazar in Sevilla.

Completely stumbling on the Trevi fountain. Had no idea that it was just around the corner, and then bam, there it was, larger than life.

Seeing Siena's cathedral up on the hill from across the valley.

The gigantic ancient bridge in Spoleto, Umbria.

The ruined cathedral in Lisbon.

Capo Testa, Sardinia. See it for yourself.

St. Stephens, Vienna. Gigantic and so dark and moody.

Terezin, Czech. Incredibly horrifying and moving tales, pictures, and scenes of the Jewish internment.

The Cala Rossa in Favignana, Sicily. Water so green, it was incredible.

I have lived in the NY area my entire life, and every time I see the Statue of Liberty I am awestruck. Another worth mentioning - walking inside Lambeau Field in Green Bay for the first time.

RED SQUARE IN MOSCOW

I have seen many jaw dropping sights in my travels, but the one that blows them all out of the water was when I first saw Red Square in Moscow. It was around 11 pm so all of the surrounding buildings were brightly lit. It sent a chill down my spine as I walked past Lenin's tomb toward St. Basil's Cathedral.

I grew up in small town America hearing so much about Russia, mostly bad. I'm not saying it's all true, but this is what they taught us back then. As a child I never dreamed I could actually visit that country, but thank God the world has changed so much and the Russians are our friends. I cannot fully describe the thrill I felt to actually be in the heart of Moscow and to see these wonderful sights I grew up thinking would be off-limits to me.

When you exit your cave dwelling in Oia, Santorini and see the incredible Caldera and the deep blue Aegean sea thousands of feet below, you're awestruck. To see the Parthenon in Athens, paticularly at night, is stunning.
Mark

This is an interesting thread, and it's giving me great ideas where I should visit next . . .

I think most of my answers have been mentioned, but I'll concur on the Grand Canal in Venice, the Colosseum in Rome, Sagrada Familia in Barcelona, and the Sistine Chapel. I remember saying a lot of "wow," and "oh my god." The first time I saw the interior of Notre Dame and the Eiffel tower were pretty spectactular also (and the light show can still make my jaw drop).

When I visited the American cemetery at Normany, I'm not sure if my jaw dropped exactly but it was certainly emotionally overwhelming. As was the Arizona Memorial at Pearl Harbor. The wall with all the names is pretty jaw-dropping.

For sheer natural beauty, the Swiss Alps are hard to beat, although I'm embarrassed that I have yet to see the Grand Canyon.

Great thread. And don't be embarressed, I'm sure you'll see it eventually.
After arriving late, waking up in our hotel room to the view of the Rialto bridge in Venice and turning around to see my husband sleeping soundly, brand new wedding ring clearly visible on his finger.

My 7 year old sons reaction when he walked out of Penn Station and saw the NY skyline for the first time. His eyes went from his feet to the sky in one slow scope, mouth agasp, with a long winded "whooooooo". Oh, I wish I had a camera pointed at him.

Three generations of family, from my 76 year old Father to my 5 year old son, all on horseback &lt , on a 3 hr. alpine trail through Wolverine Pass to Tumbling Glacier in Yoho National Park, British Columbia. We had the pass and glacier to ourselves, and had the gift of seeing a grizzly sow and her cup watching us from a hill, and we lived through it!

The color of the water at Moraine Lake.

The view from Kicking Horse mountain in Golden, British Columbia. Felt like I was on top of the world.

Ground zero.

Our sunsets on the West coast of Florida. After 40 years, I never tire of them.

Stuck in traffic on Clearwater Beach, three young kids in car seats, two sleeping, while watching a water spout form. As we slowly advanced in traffic, it became the size of a "Dorothy and Toto" waterspout . It was enormous and very near to us in the middle of Clearwater Harbor traveling the same way I was heading. Trying to figure out what to do, when suddenly it dissipated.

topping

USA:
Grand Canyon(it's impossible to exaggerate the sheer scale and grandeur of it),
Giant Rewood grove (again, you feel so small),
Yellowstone (the vast yellow plains with steam rising up out of the ground is eirily breath taking - it's other-worldly)
Lake Tahoe in spring (gorgeous)

Europe:
Evensong at Westminster abbey (moving and grand),
The lobby at Tate Modern (especially when you are among the last to leave at night. Its the largest empty indoor space I've been in. and I was alone. and it was dark, brrr...)

I'm a relative europe newbie though, so hope to add more to the list

when i first saw Amsterdam's redlight district as a 20 year old!

everything I saw as a young college student on a year+ abroad in Europe.

Now still everything....Kalalau trail in Kauai, the duomo in Milan, the long cheese isles in the super markets in Wisconsin LOL

If you love to travel the newness of every place you visit is exciting.That is the way I see it anywho! Not about comparing more about noticing the unique qualities of a new destination.

The American Cemetery above Omaha Beach.Nefretari's tomb in the Valley of the Queen's.Petra in Jordan.

Agree with Sarah that every new destination can make my jaw drop. This thread gives me such inspiration - there are so many places to see!

Here are a few of my memorable ones... some man-made and wondrous for that very reason, some evidence of the amazing power of nature:
Salisbury Cathedral.
The view from the Eiffel Tower.
The cliffs of Tintagel.
The Acropolis in Athens.
The view of the caldera on Santorini - I was so overcome that I wept.
Conwy castle, Edinburgh castle, Windsor castle.
"The Thinker" in the rose garden at the Rodin museum.
London as seen from the roof of St. Paul's.
Sydney harbour during the Olympic closing ceremonies, the bridge exploding with fireworks.
The Swiss alps.

And flying home over the mountains north of Vancouver. The lush greenness, with hidden mountaintop lakes, suddenly giving way to the Georgia Strait dotted with its islands... I take it for granted but seeing it through fresh eyes makes me realize how special it is.

I'd have to say Agua Azul (waterfalls) in Mexico near Palenque, Palenque - the ruins at sunset, Monte Alban, the cathedral in Oaxaca City that holds the Monte Alban gold, The Notre Dame Cathedral aglow on the Seine, my first plateau de fruits de mer (seafood platter) - so enormous we couldn't stop laughing - and it was MY appetizer!!, the inside of Chez Julien in Paris, the first time I saw the turqoise waters of the Caribbean, Scuba diving in Grand Cayman off the north wall and going through a wall of huge tarpon-tarpon alley, a huge wall of barracuda while diving in the Caymans, and finally Enchanted Rock in Texas- a pink granite batholith beyond words.

Staying at Larnach Castle on the Otago Peninsula near Dunedin, New Zealand watching the sun rise over the peninsula. It was so beautiful I didn't even want to wake my now ex husband to share the sight. I just wanted to savor it for myself.

Driving through Iceland in November along the foggy deserted highway I had my jaw dropping experience as we came upon the Iceberg Lagoon. A surreal mist hung in the air as huge turquoise blue and white chunks of ice gently floated in the bay. My husband and I were all alone in this magical place and my imagination could have never prepared me for the sight. As we cross the highway to check out the black sand beach, we were amazed to see thousands of pieces of ice in various sizes and shapes lying on the sand and bobbing in the surf. The contrast of the very black volcanic sand and the glistening see-through ice melting ice was unbelievably beautiful.

The View from the Eiffel Tower

Seeing Notre Dame for the first time from the Bateau Mouche

Saint Chapelle

Though, not jaw dropping, but pulling at my heart strings, attending a special service at Notre Dame.

Who knows if anyone will read my reply here, since I'm definitely coming in on the end of things here, but I just HAVE to say: My jaw-dropping experience was definitely the Trummelbachfalles in Lauterbrunnen, Switzerland. I know I can't do it justice with a description here, and pictures don't do it justice either. I will say though that it's AMAZING and TERRIFYING. The water rushing through this mountain is from 3 melting glaciers; it has carved out a corkscrew path through a mountain and you can go inside, following its path. It was so SCARY standing next to this massive amount of water rushing down. The only thing I can compare it to is, at the zoo, being right up next to a full-grown lion, with only iron bars separating you from him. That's how incredibly powerful this waterflow was.

1. Emerging from the train station and looking up to the Temple of La Sagrada Familia in Barcelona.
2. Machu Pichu in Peru
3. Iguazu Falls in Argentina/Brazil
4. Venice Grand Canal

Michelangelo's Pieta at St. Peter's brought tears to my eyes. And the collection at the Hermitage in St. Petersburg really took my breath away.