Monuments to Visit in Washington D.C.: Capitol Building – Book your tickets early. You need forethought to visit the Captiol; tours must be booked in advance, and as you'd expect, slots fill up fast. You can book your tour through your Senator, Representative, or on your own online.
There are a limited number of same-day passes available each day, distributed at the information desks in Emancipation Hall on the lower level of the recently completed Capitol Visitor Center (for which all visitors should thank the U.S. taxpayers, who footed the exorbitant $621 million bill — more than double the original projected cost). Tours begin and end here at the Visitor Center and continue through the Crypt of the Capitol, the Rotunda, and National Statuary Hall.
Monuments to Visit in Washington D.C.: Capitol Building – Nearby: Next door you'll find the charming Botanic Garden, and on the other side the formidable National Gallery of Art. And don't miss what's behind: the Thomas Jefferson Building of the Library of Congress (which you may, like me, find more appealing inside than the Capitol itself) and the Supreme Court. If you're hungry, try the native-foods cafeteria at the American Indian Museum, two doors down.
Monuments to Visit in Washington D.C.: Capitol Building – Transit: The Capitol South metro (blue, orange) is just a few blocks south of the Capitol Building. (Unsurprisingly, it seems to have the most reliable escalators in the metro system.) As for buses, the Union Station-Navy Yard Metro Circulator goes right by, connecting Union Station metro (red) with Navy Yard metro (green). Regular routes that run around the Capitol are 96, 97, A11, 32, 34, and 36.
Monuments to Visit in Washington D.C.: FDR Memorial – The best memorial in DC. This is, according to one humble opinion, the best memorial in the city. Visitors experience the monument from the inside, strolling through a series of outdoor stone "rooms" representing the various stages of an important presidency that stretched a remarkable 12 years. Franklin Delano Roosevelt was elected to four terms in an era without a two-term limit (he died a few months into his fourth term), and the monument offers an intimate and thought-provoking journey through that time.
Besides, there are waterfalls cascading over carefully disheveled rocks, profound quotes carved tastefully into the walls, and life-size bronze statues of downtrodden depression-era people standing in breadlines (great photo op: you in breadline). The waterfalls are lit up at night, making this a romantic and serene place to take someone special.
Monuments to Visit in Washington D.C.: FDR Memorial – Nearby: You're next door to the monument to MLK Jr., established in 2011. You're just up the road from the hidden George Mason Memorial and the not-so-hidden Thomas Jefferson Memorial. At a certain time of year, this is a good place to see some cherry blossoms.
Monuments to Visit in Washington D.C.: FDR Memorial – Transit: Driving is the easiest option, though parking is limited (on street). The D51 bus is another good way to get here. If you're up for a walk, from the Smithsonian metro station (blue, orange), walk west past the Washington Monument and south around the Tidal Basin.