Brookline artist Janet Echelman's phenomenal one-ton aerial sculpture went up over the Greenway in May and will loom over Fort Point Channel Park into October. It spans 20,050 square feet and includes around 500,000 hand-tied knots.

Liz LaManche, the artist behind Boston City Hall's Stairs of Fabulousness, finished these giant tattoos last fall on the shipyard's pier.

M.I.T. in April unveiled this memorial to the campus police officer Sean Collier, who the Boston Marathon bombers murdered two years before. Thirty-two solid granite blocks form a five-way stone vault, creating a central, covered space for reflection, according to the university. M.I.T. architect J. Meejin Yoon designed it.

At 38 feet high (with 11 feet underground mooring it), this bronze monument depicting the first president in his Revolutionary garb is one of Boston’s biggest single pieces of public art. It was sculpted by Thomas Ball.

Crafted by Victor Walker in pink granite, this monument in the Public Garden honors the more than 200 people with Massachusetts ties who were murdered on Sept. 11, 2001.

Unveiled in 1903, it commemorates Joseph Hooker, who commanded the Army of the Potomac in 1863, declaring, “May God have mercy on General Lee, for I will have none.”

Perhaps the most famous Civil War memorial in New England, thanks to the movie "Glory," the bronze relief by Augustus Saint-Gaudens commemorates the first African-American regiment in the U.S. Army.

The interactive bells designed by Paul Matisse, grandson of Henri, along the Charles River Dam were restored a couple of years ago.

Remarkably creepy and cool at the same time, these five life-size painted-steel silhouettes—four minutemen and a Victorian-era woman—commemorate George Washington’s siege of Boston in 1775. Designed by Madeline Lord in the late 1980s, they are spread over Fort Washington Park.

Using steel, steam, light, honey locust trees and greenwave shrubs in Thomas J. Murphy Park, a team of M.I.T. artists in 1990 collaborated with landscape architects, urban designers and engineers to make this multi-stage work more akin to a Kiss concert than to public art.

The Isabella Stewart Gardner Museum unveiled the redesign of the gardens in September 2013. Michael Van Valkenburgh designed the greenery (he also put the chairs in Harvard Yard).

The statue of the Red Sox great was unveiled in September 2013 outside of Gate B at Fenway.

It's certainly... interesting, this bronze depiction of a giant Clapp pear unveiled in 2007 by Somerville artist Laura Baring-Gould.

Shinique Smith created this 70-by-76-foot temporary mural in Dewey Square, which was installed in September 2015 and will be on display through August. The work is part of a larger exhibit by Smith at the Museum of Fine Arts.

The granite sculpture by Robert Shure and Robert Lamb was installed in Copley Square in 1996 to mark the race's 100th anniversary. It has, of course, in the last two years taken on a different, deeper meaning.

The memorial commemorates the famine that started in 1845 that led not only to hundreds of thousands of deaths, but to a mass emigration to the U.S.