By Elliot Carter

There are two unmarked stone towers on the western slope of the Capitol Grounds. Overshadowed by the Capitol dome and downplayed by blocking shrubbery, most people walk by without noticing them.

These are the end caps for two massive air ducts leading 400 feet up into the belly of the Capitol. You can see the 15 food wide passageways marked here in a 1961 map. The asymmetry of their layout corresponds to differences in elevation on the House and Senate side of the hill.