The waterfall plummets 1000 feet...

[Dioltach]

Uluru. "What do you mean, there's a giant rock sitting in the middle of the desert? That doesn't make sense: how did it get here? Man, talk about an obvious adventure hook!"

And from personal experience: the weather in the Rocky Mountains. "What do you mean we're stuck in a snowstorm? It's the middle of summer! Did we do something to annoy you? Just a second ago you said the weather was fine!"

 

[Joakar]

I find religions to be continually awe-inspiring and at the same time puzzling. Consider Islam and its duty of pilgrimage: once in their lives, each and every muslim must travel to the Mecca, specifically to the Kaaba. This pilgrimage is called the Hajj, and it's a pillar of their religion. Another thing, the Kaaba is the place where they orient their prayers and the physical center of their faith.

I find that if you present this kind of thing to players in a campaign, it's very (VERY) difficult to do so while maintaining a sense of verosimilitude.

 

[IronWolf]

Mammoth Cave. At 390 miles, that would take a lot of graph paper to map out that dungeon.

h yeah! Mammoth Cave is another great one! My mind always slips to fantasy caves and caverns when we visit there!

 

[PaulofCthulhu]

So what have you seen in the real world that is too cool for the D&D world?

- The pyramids of Egypt (inside and out)
- The city of Petra (there's more than just the "Treasury".
- Buried Mayan pyramid temples, as complete as when they were built - excavated after 1,000 years and lit in a dark cavern by beams of light.
- Secret Mayan king tombs, newly found and untouched.

Other things I cannot tell.

 

[Man in the Funny Hat]

So what have you seen in the real world that is too cool for the D&D world?

My short list is probably...
-- Grand Canyon
-- Yosemite waterfall
-- Schloss Neuschwanstein
-- Angkor Wat

Not a world traveller but my list would otherwise include:

• Great Wall of China
• Angel Falls
• Dry falls (when it was still wet...) Dry Falls, Washington, USA.
• Eiffel Tower
• Golden Gate bridge
• Colosseum in Rome
• Christ the Redeemer in Rio
• Panama Canal
• Hoover Dam
• Bell Rock Lighthouse

Wonders of the World - Wikipedia, the free encyclopedia is a good place to start such a list.

 

[pauljathome]

The underground cities in Capadocia (Turkey)

Pretty much all of Nepal

Pretty much any glacier (New Zealand in particular has lots and lots of glorious examples)

Great Barrier Reef

 

[Dross]

The moon and Mars have a number of natural formations that dwarf their Earth counterparts. Martian "canals" and "faces" spring to mind as well.

 

[Crazy Jerome]

In a canoe, when there is reasonable rainfall, you can travel from the extreme southern tip of Marshall County, Alabama to the Gulf of Mexico in Mobile, and never touch land once. This is about 300 miles of navigable waterways--about half of it small rivers.

Maybe not very impressive when from the hills of Eastern Tennessee, you can go to New Orleans on the Tennessee River and Mississippi Rivers. Yet, with a 15 mile portage at Guntersville, AL, a canoe starting from those same Eastern Tennesse hills could cut the trip in half.

In a fantasy environment, when a small group has to get somewhere without a lot of baggage, in a hurry, they might have some surprising options.

 

[AeroDm]

I should probably add Big Sur. It is one of the only places in the world with elevations above one mile within one mile of the ocean. In other words, the land rises at a 45-degree angle or better for a full mile.

 

[Smoss]

Less geophysical and more geopolitical, one of my PCs looked at one of my countries that has 19 separate cult controlled (but allied) areas and said something like:

"You cant have 19 things like that, the only example in the world is the US with its 50 states."

I had, of course, done research on my world to keep it feeling real - Pointed him to details on Iraq - Which is about the same size as the country I created. Iraq has 18 provinces. 18 vs 19 for about same land area. I think I hit the number about perfectly for a real world feeling.

I'll just call the PC a little too misinformed about the world outside the USA.
Smoss