Some quick advice needed please...
I am being dropped off at DCA and will have about 6 hours to spare before the flight. We want to get some quick sight seeing in and it looks like the easiest way to do this is the metro station at DCA. First, is that the easiest way for transportation? It appears that most attractions are very close to the airport.

Second, does anyone know where we can store our carry on bags for a few hours. I doubt there is storage at DCA but does anyone know if there are lockers at the metro stations or some other location?

Thanks!