Washington DC does not have a skyline, or at least not a high-rise skyline. The tallest structure (by far) in the city proper is the Washington Monument, topping out at 555 feet. I live in Silver Spring, Maryland, in a tenth-floor apartment, and my windows face south into the District. I can't see the Monument, which is about six miles distant, but I suspect that's only because of another building in the way. I can, however, see the spires of the National Cathedral, especially in the winter, when the trees in Rock Creek Park thin out. Mostly, though, my view is lush and arboreal, and looking south there's nothing to suggest the massive geo-political power concentrated in the low-rise federal city.
Or almost nothing. If DC lacks a skyline in the usual sense, my picture window view has allowed me to glimpse another. After dark I can see the lights of passenger jets rising in and out of Reagan National airport, for instance; sometimes I can see the actual aircraft in the day, but at night they are visible only by their approach lights, which slowly sink into the horizon. If the daytime weather is right, contrails from patroling fighter aircraft are also visible, 20,000 feet straight up. Closer to home, helicopters pass overhead regularly, inbound or outbound from the District. There's no way to know who's on board, but it's easy to speculate of course. The constant array of civil, federal, and military aviation is perhaps the city's real skyline, an ever-changing pointilist composition of running lights and flashing beacons.
There are other things to see too. Lightening storms are spectacular from up here. And looking south into the District on 9/11 I saw the smoke from the burning Pentagon, moments after the first media reports of an explosion there. Do I worry about one day seeing even darker clouds on the DC skyline? Of course I do.