More than 330 million people visited the 418 units of the National Park Service last year. Familiar names like Great Smoky Mountains National Park, Blue Ridge Parkway and Lincoln Memorial each snag millions of visitors each year.

But also tucked into the nooks and crannies of the system are places like Thaddeus Kosciuszko National Memorial in Philadelphia. The tiny site, which at just 0.2 acres in size is also the smallest unit in the NPS system, saw just 2,077 visitors last year. It was the eighth least visited site in the system.

The white-shuttered brick house along Pine Street was the home of Visit the house where wounded Polish freedom fighter Andrzej Tadeusz Bonaventura Kosciuszko (1746-1817), more commonly known as Thaddeus Kosciuszko, lived and received notable visitors like Chief Little Turtle and Thomas Jefferson.

Kosciuszko was a Polish general, military engineer and revolutionary. He fought in the American Revolutionary War, as well as an uprising in his home country. He was known for his bravery, kindness, patriotism, likeability and unwavering strength of character.

Late in August 1776, Kosciuszko stepped off a ship and onto the docks in Philadelphia. After making the acquaintance of Benjamin Franklin and proving his worth by designing blockades and fortresses along the Delaware River, he was given the rank of colonel by Congress in October 1776. In December, he designed Fort Mercer in Red Bank, New Jersey. In the summer of 1777, he ordered the troops retreating from Ticonderoga to delay the British by felling trees and moving boulders onto the path, as well as diverting and damming streams to turn the woodland path into a swamp. In the autumn of 1777. His structures and use of topography contributed to the American victory at Saratoga.

Aniakchak National Monument and Preserve in Alaska was the least visited NPS site last year. Just 100 people visited Aniakchak, one of the most remote and wildest places in the NPS system. Unknown to anyone other than native people in the region until the 1920s, it is located in the volcanically active Ring of Fire, and is home to a 6-mile-wide, 2,500-foot-deep caldera formed during a massive volcanic eruption 3,500 years ago.

The second least visited site, the Mary McLeod Bethune Council House National Historic Site in Washington, D.C., saw 109 visitors last year.

The Council House was the first headquarters of the National Council of Negro Women and was Bethune’s last home in Washington, DC. From there, Bethune and the NCNW spearheaded strategies and developed programs that advanced the interests of African American women.

The third least visited site of 2018, Rio Grande Wild and Scenic River, Texas, would not make the least-visited list if considered as a whole, but the wild-and-scenic section of 196 miles was visited by just 330 people last year. They witnessed some of the more remote vistas in the Chihuahuan Desert.

No. 4 on the list, the Clara Barton National Historic Site in Maryland was visited by 425 people in 2018. Barton, who spent the Civil War tending to wounded soldiers close to the battlefield, founded the American Red Cross in 1881 and served as its president until 1904. Her house in the Washington suburb of Glen Echo, Maryland, was the early headquarters for the organization.

The Port Chicago Naval Magazine National Monument near San Francisco, California, with 653 visitors in 2018, was the fifth least visited site in the NPS system last year. On the evening of July 17, 1944, residents in the San Francisco east bay area were jolted awake by a massive explosion that cracked windows and lit up the night sky. At Port Chicago Naval Magazine, 320 men were instantly killed when two ships being loaded with ammunition for the Pacific theater troops blew up. It was World War II's worst home front disaster.

The sixth least visited site last year was Alaska’s Yukon-Charley Rivers National Preserve, where just 1,272 visitors ventured in 2018. Located in Interior Alaska, Yukon-Charley Rivers offers exploration in a largely untouched landscape. Access to the preserve is limited to water or air travel during the summer season and air or various means of adventurous options (including snowmachines) during the harsh winter months.

The Carter G. Woodson Home National Historic Site in Washington, D.C., was the seventh least visited site in 2018, with just 1,954 visitors. Before Woodson, there was very little accurate written history about the lives and experiences of African Americans. The home served as the headquarters for the Association for the Study of African American Life and History, and Woodson established Negro History Week there in 1926, which we celebrate today as Black History Month.