Here’s an old Mad Men-era advertisement for apartments in Arlington. The building still exists, and the rent is substantially higher than what’s listed below in the 1960s ad. Click on the ad for a larger version.

1850 Columbia Pike, Arlington
Here’s the Google Street View of the building today, now called The Wellington.
[googlemaps https://maps.google.com/maps?cbp=12,142.68,,0,0&layer=c&panoid=NywNGgICGT8aVQQEobEWVg&cbll=38.86506,-77.077276&ie=UTF8&ll=38.832754,-77.036133&spn=0.365323,0.695572&t=m&z=11&source=embed&output=svembed]