The Guam Congress Building, on Chalan Santo Papa next to the cathedral, is the seat of the Legislature of Guam (Lehislaturan Guåhan). The building, completed in 1947 in a sober tropical-modern style, is the working chamber where Guam's twenty-one senators meet — and the only legislative building in any U.S. territory outside the fifty states open to casual visitors.
You can enter the lobby during weekday office hours and look at the small permanent display on the history of Guam's representative government, from the Spanish-era cabildo through American territorial status to the present. Legislative sessions are open to the public; the schedule is posted at the entrance. Quick visit — fifteen minutes — best combined with the cathedral next door.