you can rent e-bikes with capital bikeshare and I feel like you can theoretically dock them in national harbor and ride from there across the 495 to old town alexandria and then if you were really fit over into dc and you could theoretically loop back via anacostia/suitland but i've never done the full loop
but the part between national harbor and alexandria is interesting and the mt vernon trail runs near the water

the connection between national harbor and the bike trail is weird though like you have to access it at a really specific point to connect between the little town and the 495 bridge bike/pedestrian access so i recommend having the capital bikeshare app open to figure it out and it was closed at one point I think but that was like a year ago

I assume you are coming for a conference?
dc is kinda bland
there's the waterfront and navy yard basically the sections of the city on the potomac river (as well as georgetown on the potomac very popular with tourists as well with fancy shopping too), waterfront is newer and has like expensive trendy restaurants some overlooking the water as well as a walking/biking path on the river
I really enjoy the anacostia riverwalk biking trail the part between the roller rink (srsly) and bladensburg waterfront is very pretty if you see one thing I would do that I'm biased towards biking but its a good way to see the city and the rentable ebikes make it easy you will need a balaclava tho and heavy pants and a thick jacket its winter and you will need boots or shoe covers sneakers are unpleasant to bike in in winter

also you need to reserve in advance but you can go up the washington monument and the view is nice from the top
not sure if you will have a car or be driving or flying in, but if you ever get a chance harpers ferry about 1.5 hour drive outside the city is quite scenic there's a 5 minute walk from the train station to where the shenandoah river meets the potomac river and then a 2 hr hike 1200 ft up to a view of the town from a high point

for me the surroundings are prettier than the city
the city is bland government architecture
but I would say walking/driving/biking h st gives you a decent sense of the city and some of the more interesting buildings, I recommend 11th st if you are going north/south it also has a good bike lane and wide streets for walking

you used to be able to take the elevator up to the rooftop terrace in the kennedy TRUMP center without paying for a ticket not sure if they still allow that
and the old post office building that became the trump hotel i think its a waldorf hotel now anyways they also have a (I think free?) elevator to the top for tourists that I enjoyed a lot as a kid.

and not sure when you are coming but in february and into early march there's pink plum blossoms that blossom near the world war 1 memorial and in a few other places on the mall
and there's the indoor conservatory of the us botanic garden that is heated and warm in winter

>>2851593
Go to succotash. The food is bonkers Korean southern fusion. You might be there during the magfest convention in which case you could people watch for hours