Robert Smithson's "Spiral Jetty" is made of mud, salt crystals, basalt, and dirt. Though it extends a whopping 1,500 feet in the Great Salt Lake, it can only be seen under certain conditions.

This lavish 16th-century mansion has several spiral staircases, the most impressive of which is known as the Scala Regia. Inspired by a grand staircase at Pope Julius II’s Casino di Belvedere, the Scala Regia features frescoes by Antonio Tempesta and is large enough to be ascended by a mule or a small horse.

The ultra-modern chapel was designed by Japanese architect Hiroshi Nakamura who set out to create a building that could in itself evoke the coming together of marriage.

Within the Naturerbe Zentrum Rügen (Rügen Natural Heritage Center), a treetop view tower nicknamed the "Eagle’s Nest" is a stunning structure. A spiraling walkway surrounded by greenery slowly winds its way up and around a 100-foot-tall copper beech tree. The only thing more impressive is the incredible views from the top.

Built circa 3200 B.C., during the Neolithic era, these ancient tombs in the Boyne Valley in the Irish county of Meath predate Stonehenge and the Pyramids of Giza. Newgrange was built with astronomical alignment: On the morning of the winter solstice, the central chamber is briefly illuminated by the rising sun's rays.

In downtown Dallas, Thanks-Giving Square is a meditative and serene urban garden located 15 feet below ground level. Its spiritual center is the spiral-shaped Chapel of Thanksgiving, which explores unity while representing the diversity of different faith and traditions.

At 109 feet deep and 32 feet wide, the aptly-named Big Well is the largest hand-dug well in the United States. An illuminated spiral staircase leads visitors to the bottom of the well, which has been declared one of the eight wonders of Kansas.

Made out of rock and shaped like a corkscrew, this barn towers above the surrounding countryside, looking more like a medieval keep than a farm building.

With its spiraling facade, this tower essentially looks like a giant drill bit poking above the trees. Its purpose? To test new elevator technologies. The German lift manufacturer ThyssenKrupp began building this 800-foot-tall tower in 2014. It uses magnetic levitation to pull its ropeless elevators both horizontally and vertically.

Nothing seems to distinguish the two buildings situated on the 54 and 56 Boulevard Daguerre that seem to blend like chameleons into the urban landscape of Saint Etienne. But the two constructions known as Les Chalets de Bizillon hide an architectural curiosity; a helicoidal, gently sloping ramp serving the six stories, elevating its spiral as a mezzanine around a decorative indoor garden on the first floor.

Copenhagen's Rundetårn (Round Tower) is noted for its lack of stairs. Instead, a smooth slanted ramp winds itself 7.5 times around the hollow core of the tower, creating a 964 foot-long path up to the top of the former observatory.

Rising out of a flat expanse in the Egyptian desert, the earthen cones of Desert Breath seem like giant, alien ant hills, but they are simply art. The work of land art, which was completed in 1997, consists of a fractal spiral of alternating cone-shaped protrusions and depressions.

The headquarters of the Community of Christ Church is eye-catching even to the undevout. The central spire of Independence Temple was designed in the shape of a nautilus shell reaching up to the heavens. It required four years and over 300 panels of custom-built stainless steel—all in the days of early 1990s software imaging.

Among the more striking features of this four-hectare estate are two structures called the Initiation Wells. With spiral staircases that lead deep underground, these wells were used for ceremonial purposes, rather than water collection.

Conspiracy theories and occult legends surround this mysterious natural rock formation and the manmade stone spirals that surround it.

This corkscrew bridge drives locals loopy in the center of Japan’s scenic Izu Peninsula. Completed in 1982 to cover terrain too steep for a conventional road, the bridge is an intriguing landmark on the route from Tokyo to the hot-spring resorts in the nearby city of Shimoda.

The Swiss artist Méret Oppenheim is known for her vast surrealist oeuvre. One of her last masterpieces can be found in the heart of her chosen home of Bern. Spirale (Gang de Natur), or The Spiral Column (Nature's Way), is made of concrete and aluminum, and functions as a fountain with water running down the outside.

A spectacular spiral staircase leads to the top of the tower, designed by architect Charles Rennie Mackintosh and completed in 1895. Climb to the top, and you’ll have wonderful, vast views over Glasgow.

A paved road spirals up and around to the rim of Capulin Volcano, making it one of the most accessible volcanoes in the world. Volcano Road, as it is known, is one of the most remarkable roads in the state, and is in itself an attraction.

Sitting above the town with which it shares a name, the Crestone Ziggurat is among the most noticeable—and scenic—of the settlement’s spiritual structures. Visitors can climb the spiral ramp to the top, which offers stunning views of the surrounding area, making it a perfect spot for quiet contemplation.

Completed in 1438 under the guidance of Holy Roman Emperor Frederick III, the Burg of Graz was expanded by Frederick’s son, Emperor Maximilian, from 1494-1500. When reopened, officials and civilians marveled at the Doppelwendeltreppe (Double Spiral Staircase) that traveled two floors to the top of the tower. The staircase splits and rejoins several times as it circles upward to the top, and has often been interpreted as a symbol of eternity.

With a spiral staircase and spherical top, Sooner Park's Playtower was inspired by both the Space Age and the continuous 360 degrees of the Möbius strip.

The copper-clad wooden spire was a late addition to this Copenhagen church. A set of 150 stairs run counterclockwise up the tower, looping around four times before reaching the top.