The large chamber of the Hiram M. Chittenden Locks in Ballard was drained this week so the Army Corps of Engineers can inspect and clean the 100-year-old structure, the busiest locks system in the country. The annual draining reveals a glimpse of the sea-anemone-covered floor, and a trip inside gives you an appreciation of the incredible scale of the 55-foot deep, 85-foot wide and 800-feet long chamber.