Yes, most room reservations are refundable if you cancel before the hotel's cancellation deadline, which is often 24 or 48 hours before your check-in date. If you have a reservation that's non-refundable, it may still be possible to cancel it and receive a refund within 24 hours of your booking. Plug in your dates, click on "Search", then you can use the "fully refundable" filter to review top deals close to Plaza San Martín.