Nature usually has a monopoly on wonder, but every once in awhile we humans cobble together something that's truly awe-inspiring. Massachusetts is full of beautiful man-made structures, and we've selected a few landmarks that are particularly stunning.

1. Pilgrim Monument, Provincetown

This towering structure is one of Cape Cod's most beloved man-made landmarks. It was built in 1907 to commemorate the arrival of the Pilgrims in 1620, and it's the tallest all-granite structure in the United States. Visitors can climb the 252-foot tower and gaze over Provincetown and Cape Cod from its airy top. Can't face the thought of all those stairs? In fact, ramps are used to climb most of the way up the tower, though there are 116 steps at the bottom and top.

2. 1826 Round Stone Barn, Pittsfield

This unusually-shaped stone barn was built in (you guessed it) 1826. It's the only circular barn ever built by the Shakers, and is widely recognized as an architectural wonder. Wagons would be driven into the barn, around the interior and back out the same entrance, eliminating the need for two entrances or the dangerous practice of backing wagons out. Today, the massive structure is a museum dedicated to educating the public about the Shakers and local history.

3. The "Witch House," Salem

Formally known as the John Ward House, this gloomy-looking structure was one of the first colonial-era houses in the United States. Like many sites in the magical town of Salem, the home is rumored to be haunted. The ghost of a witch and the man who killed her are said to dwell in the little black home, and it's easy to see why locals and visitors alike get a spooky vibe from this historic abode.

4. The Bridge of Flowers, Shelburne Falls

The Bridge of Flowers is the perfect blend of man-made and natural wonder. A garden of flowers runs along the length of this 400-foot bridge. The colorful pedestrian bridge was built in 1907, and has been blooming since 1929. The bridge is covered with flowers for most of the spring and summer, and is truly one of the most romantic places in the state.

5. Fenway Park, Boston

Fenway Park is the oldest stadium in Major League Baseball. It's a Boston landmark and one of the most recognizable athletic stadiums in the world. The distinctive verdant hue of the Green Monster is so classic, it's actually a trademarked color. If you've never been to see a Red Sox game here, you're missing out on a piece of American history...and some awesome ballpark franks.

6. USS Constitution, Charlestown

"Old Ironsides" is a floating Massachusetts landmark. First commissioned by George Washington in 1794, the USS Constitution is the oldest active naval vessel in the country. It's also the only remaining active duty ship to have sunk an enemy vessel. The craft is currently in the midst of a restoration and repair effort, and will be available for public tours again soon.

7. Zakim Bridge, Boston

This cable-stayed bridge was opened in 2003 and carries 10 lanes of traffic across the Charles River each day. Visually stunning, this style of bridge is slowly gaining popularity across the United States.

8. Trinity Church, Boston

This is one of the most distinctive-looking churches in New England. Trinity Church was founded in 1733 and built in 1872. Its striking Richardsonian Romanesque architecture, bold coloring and massive towers made it an instant landmark in the city. The church is located in bustling Copley Square, directly opposite the next amazing structure on our list.

9. Boston Public Library, Boston

Massachusetts was the first state to offer a public library, and the BPL is a testament to our love of learning. The library itself contains over 23 million items, with more items in storage. It's the third largest library system in the country, behind the Library of Congress and the New York Public Library. Besides the numbers, the library building is truly stunning. The main reading room is cavernous and awe-inspiring, and the McKim building resembles a palace.

10. Veteran's War Memorial, Mount Greylock

This memorial monument to the nation's warriors sits atop the highest peak in Massachusetts: Mount Greylock. It looks like a fantastical lighthouse, and is one of the most striking manmade features on the mountain. The area around the monument is a popular place for picnics and photography, due to the incredible views afforded by this lofty perch.

Looking for more Massachusetts beauty? Check out the 15 most incredible natural wonders in Massachusetts.