The nation's only public museum and memorial dedicated to World War I features the 217-foot-tall Memorial Tower, which opened in 1926 and offers views of downtown Kansas City from its top (which you can skip), and a fascinating underground museum documenting the history of the "Great War" (36 nations were involved) with touch screens, films providing an overview of the war and America's entry into the conflict, and the largest collection of World War I artifacts in the United States, much of it donated. Exhibits include photographs, uniforms, letters from the field, weaponry (like the world's only remaining Bavarian Howitzer and a French Renault FT17 tank), and displays that give a human dimension to the conflict, including life-size trenches that defined the Western Front. Most people spend 2 to 3 hours here, but you could easily stay the entire day.