U.S. Landmarks Everyone Should Visit

School is out, but history is always in. (Good luck with those 'Hamilton' tickets.) These experts, including a national-park photographer and a Smithsonian Institution director, vote for their must-sees.

This story originally appeared on realsimple.com 1. Gettysburg National Military Park, Pennsylvania Most historians agree that the battle of Gettysburg was the turning point in the Civil War; it saw more casualties than any other battle in Ameri­can history. You can explore the battle­fields alone, with a guide, or even on horseback. Definitely see the national cemetery near the High Water Mark, where the Union dead are buried and where Abraham Lincoln delivered the Gettys­burg Address. But remember that Gettys­­burg is more than a battlefield and a burial ground. The Eisen­hower farm, the retirement home of President Dwight Eisenhower, is part of the park. And there’s the Eternal Light Peace Memorial, just north of town, which is especially mean­­ing­ful to me. I think about the dedication by President Franklin Roosevelt, in 1938, to honor the 75th anniversary of the battle. While FDR spoke about the value of peace, the rest of the world was preparing for war. —Brent D. Glass is the director emeritus of the Smithsonian Institution’s National Museum of American History and the author of 50 Great American Places: Essential Historic Sites Across the U.S. He lives in Washington, D.C. Related: How to Plan a Family Weekend Getaway 2. Yellowstone National Park, Wyoming, Montana, and Idaho I’ve photographed a lot of national parks. I’m on assignment for National Geographic, visiting all 59 national parks for the 100th anniversary of the U.S. National Park Service. But I could spend years shooting Yellow­stone and never capture its entire essence. You’ve got bison roaming freely, prismatic springs that paint rainbows on the ground, geysers.… Yellowstone was America’s first national park, so in addition to being beautiful, it paved the way for land conservation. That is a uniquely American idea and, I think, might be our greatest gift to the world. —Jonathan Irish is a photographer who has shot for National Geographic, the New York Times, and CNN. He lives in Washington, D.C. Follow his national- park project on Instagram (@jonathan_irish). Related: JetBlue Has a Genius Idea for Dealing With Crying Babies on a Flight 3. Lewis and Clark's Missouri River route, Montana I was inspired to canoe down this stretch of the Missouri River in Montana by Stephen E. Ambrose’s* book about Lewis and Clark, Undaunted Courage. I began at Coal Banks Landing and finished at Judith Landing. Little has changed since Lewis and Clark came through in 1805, and Lewis kept such amazing notes that you can read along in his journals and experience things pretty close to the way they did. You’ll see no roads— and few people—and it’s one of the best ways I can think of to spend a week. It really helps you understand the power of America. —Andrew McCarthy is an editor at large for National Geographic Traveler and the author of Just Fly Away (out in 2017). He is also a director and an actor, appearing in ABC’s The Family. He lives in New York City. * Stephenie Ambrose Tubbs (quoted below) is Ambrose’s daughter. Related: These Summer Vacation Destinations Will Save You Money​ 4. Thomas Jefferson's Library, Washington, D.C. Jefferson’s personal collection—6,487 books that he called “unquestionably the choicest” in the United States—formed the basis of today’s Library of Congress. (Many were destroyed in a fire; about 2,000 remain and are on exhibit there now.) To see these books, know­ing how much they meant to our third president and how strongly he believed in enlighten­­ment and access to education as the foun­dations of democ­racy, is an electrifying experi­ence. It’s as if he’s whispering his favorite passages into your ear. If you love books and libraries, you will find this place extraordinarily special. —Stephenie Ambrose Tubbs works with the Lewis and Clark Trust and is the author of Why Sacagawea Deserves the Day Off. She lives in Helena, Montana. 5. Colonial Williamsburg, Virginia It is so close to Busch Gardens and Water Country USA that families are often tempted to give it short shrift—or they assume that Colonial Williamsburg is another adjacent theme park. But I think it is one of the most important historical displays in the United States. The reconstruction of the town, which started in the 1920s, is ongoing, and those Colonial-attired docents are very well trained. What I especially appreciate is that they did not overlook the contributions of the many African-Americans who lived there. The same attention to detail extends to the slave quarters as to the Governor’s Palace. —Theodore C. Delaney, Ph.D., is an associate professor of history and the head of the Africana studies program at Washington and Lee University. He lives in Lexington, Virginia.