It was Day 1 of our East Coast trip.
We landed at DCA at around lunch time and took the Metro down towards Alexandria, which was only on the next stop, but then we needed to walk six more blocks to our hotel to drop off the luggages.
We then headed back to DC and spent the whole time around hopping for the typical touristy places.
One of the Metro people advised us to take the train to Arlington Cemetery and walked across the bridge from there to the National Mall. It was quite a long walk, but fun, nonetheless. I wish I could join the crowd jogging along the Potomac River.

The National Mall, Washington DC.
Major places we went to around this area were the Lincoln Memorial, the National Monument, some of the Smithsonian museums, and the White House. We had dinner at a burger join on 12th St.
From there, we continued to visit the Basilica of the National Shrine of the Immaculate Conception which is located inside the Catholic University of America complex. We also stopped by the famous Union Station and take a peek around L'enfant Plaza. We didn't have a chance to visit the Georgetown area.
For our latenight dinner/snack, we stopped by a run down El-Salvadorian/Mexican place near our hotel. We had some sort of cassava with meat, chicken taco, and plantain with sour cream. I kinda developed a certain fondness for the Salvadorian food. They somehow tasted better and fresher then the Mexican food we usually have in CS.
All in all,we praised kudos to the Washington Metropolitan Area Transit Authority for the convenience. Schedule and destination are announced clearly on its every car and station.