Maybe it's all of the election buzz that's making us think of our nation's capital. Maybe its the cherry blossoms we wish we could have seen. Regardless, we can't stop thinking about Washington D.C. The Francis Scott Key Bridge stretches across the idyllic Potomac River -- and has since 1923, making it the oldest-standing bridge in the city's history. Yet another reason we want to head down to D.C., well, ASAP.