I parked a couple blocks away in the neighborhood for free.
Valet parking is available at The Dupont Circle Hotel. Overnight parking is $40 per night, while day parking is $21, not including tax. Reserve our Drive-in DC room package to enjoy overnight accommodations, parking, a food and beverage credit, late check-out and an upgrade at time of booking pending availability. For more information on this package, visit the offers page on doylecollection.com/the-dupont-circle.
They charge 40 or 45 dollars for parking per day and an extra 15 for valet. I tried to park the car myself to save some money and they told me I couldn't do it. I hope this helps.
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