Petra, one of the new seven wonders of the world. Petra is a series of ruins and cave-structures in Syria, one was featured in the movie
Indiana Jones and the Last Crusade. As many as thirty thousand people once lived in these canyon structures, but after an earthquake in 363 AD, much of the city was destroyed and Petra never recovered. There are 800 fantastic carved tombs, such as the one used in the Indiana Jones movie.
Temples of Damanhur which
I wrote about a few months ago, a fantastic series of tunnels excavated by an eccentric visionary and his followers. An whole complex has been built up around the temples, with their own money, farms, homes, and religion of sorts.

The
Plain of Jars in Laos. This is just an oddity, hundreds of stone 'jars' hollowed out and scattered for miles along a trade route. Were they for watering animals, catch basins for rain? Were they some kind of lunatic king's idea? Some of these are several meters long. apparently they all had lids at one point. What's worse is that there are believed to be unexploded ordnance from previous wars in the area as well.
Floating Islands of Peru, a feature that I actually
have used in my fantasy game setting without knowing this existed. These are villages actually on Lake Titicaca, as in floating upon them. Made of reed mats that float on the lake, people just live on these, selling what goods they have or collect to boats that pass by.
Mirror of Heaven, a huge salt flat in Bolivia which is often covered by a thin layer of water, perhaps an inch deep. More properly known as the Corpiasa Salt Flats, this acts as a mirror that when the air is calm is almost perfect in its reflection. Covering 4000 sq miles, this flat pan is more than 11,000 feet above sea level.

The royal
Wieliczka salt mines in Poland. Hewed out centuries ago to provide salt and commerce for the Polish kings, these mines plunge over a thousand feet down in nine levels, with more than two thousand chambers connected by almost a hundred miles of corridors. Within it are chapels, rooms, and even a cathedral with chandeliers made of salt. There is a chapel with sculptures made of salt near the entrance but the moisture has caused them to corrode and melt slightly. The link above has a wonderful story about how the salt mines were originally found.
Sedlec Ossuary in the Czech Republic. What do you do when you have more dead than places to put them? Bury them until the flesh rots off then store their bones in an Ossuary. This one has over 40,000 human remains, many of which have been built into decorations, even ghoulish furnishings such as arches and a chandelier.
Museum of the Dead. This particularly grim location is in a church in Palermo, Italy. Here, unwanted dead are stored, skin partly on the bones, often posed in gruesome, horrible mockeries of life. This place is ghoulish and disturbing, semi-mummified and partly rotted bodies of children and adults in burial shrouds, standing on shelves and in nooks carved in the wall.
Venezuelan Tepuis, several vast plateaus almost totally isolated from the lower jungle. this is almost certainly the kind of topography that inspired Arthur Conan Doyle's
Lost World story, a section of jungle that is surrounded by cliff. The landscape atop these is even stranger:
Though flat, the tops of Auyan-tepui are sometimes corrugated into sandstone mazes so intricate that you could get lost in them. Some boast sculpture gardens: balanced slabs in gravity-defying arrays and multi-ton monoliths named for their shapes—the Nun, Crocodile, the Shaman. Pools, caves, and enormous sink-holes draw climbers and spelunkers bold enough to take them on; hikers can challenge sharp and abrasive rock, shin-bashing bromeliads, numbingly cold sloughs. Little wonder that, today, many tepui visitors come and go by helicopter.
The tallest waterfall on earth, Angel Falls, roars down off of one of these Teupis.
Giant's Causeway, Found in Cornwall, this area has been featured in several movies. Legend has it this area was formed by the giant Finn MacCool, which is worth just saying a few times. Some say this once led to Tír na nÓg, an atlantis-like paradise which sunk under the waves long ago. Formed of hexagonal basalt columns of swift cooling lava, it's definitely distinct.
All around us are fantastical places, wonders waiting for you to find. I love discovering little ones nearby, such as a spot in the woods I used to play as a child that looked like hobbits lived there. The world is too big to explore it all, so vast that sometimes it is frustrating. I wish I could see more.