For romance, Monuments by Moonlight Night Tour (Old Town Trolley) delivers.
The memorials genuinely are at their best after dark — floodlit, cooler, and far quieter — and a guided loop stitches the far-flung ones (FDR, Lincoln, Vietnam, Korean War, Iwo Jima) together without the daytime heat or the long Mall walk. Old Town Trolley's version adds a live conductor with anecdotes and a few ghost stories. The catch: you're on a fixed schedule with limited time per stop, and a confident self-driver can do the same loop by rideshare for less, minus the narration.