It hit me recently when I was scurrying to an appointment in Tysons Corner. Our skylines are changing. The big buildings I once considered landmarks now seem somehow less so, dwarfed by large new neighbors.

The newest buildings appear to be a magnitude larger, like really big.

I didn’t see it at first. As editor, of course, I was familiar with our coverage about the topping off of 1812 North Moore, the 390-foot tall, 580,000-square-foot colossus in Arlington County. From the Georgetown side of the Potomac River, the region’s tallest building fits right in among Rosslyn’s glass-and-steel redwoods. But crossing Key Bridge, I gained a different perspective. Up close, the building with its steepled homage to the Washington Monument made its neighbors seem . . . lacking.

It was as if a tall, broad-shouldered, offensive lineman decided to stand next to, well, me.

I had exactly the same feeling as I approached Tysons Corner from the Capital Beltway. I once thought the 14-story Capital One headquarters was big, in a stand-out, impressive way. Same with the sprawling Gannett complex nearby. But they look like outbuildings compared to the 526,488-square-foot monster going up at the soon-to-open Tysons Corner Station. The 22-story Macerich building is huge.

If you thought Tysons Corner was bursting with offices, you haven’t seen anything yet. It’s clear we are about to enter a new age of density.

As staff writer Jonathan O’Connell points out in this week’s cover story, the two buildings share more than their bigness. They are also located directly on top of Metrorail stations, a trend sure to add new complexities not just to our daily commutes but to the way we relate to this new level of urban development.

These big projects are mini-cities unto themselves, and it will be interesting to see how long it takes them to fill up with tenants in this uncertain economy. Nevertheless, they are part of an undeniable movement toward town centers and urban living, and more are sure to follow — manifestations of our ambitions for a Washington very different than the marbled hallways that preoccupy so much of the world’s attention.