What lurks beneath the Ballard Locks?

It's one of Seattle's wonders, and through Dec. 6, you can take photos of the large chamber at the Hiram M. Chittenden Locks in Ballard as seldom seen: empty.

It's time for the annual maintenance of the 91-year-old Locks.

On Friday, the Army Corps of Engineers emptied the large chamber, with the small Lock remaining in operation.

Among items found at the bottom of the emptied 55-foot-deep, 825-foot-long chamber were what you'd expect might drop off boats and from the curious along the edge of the canal: cellphones, a two-way radio, fishing line, flip-flops, a boot, beer cans, aluminum hooks used to grab the dock and a pair of prescription glasses. The latter had been reported lost, and this week owner and glasses were reunited.

One of the tasks in maintaining the chamber is to scrape off by hand the sharp-edged barnacles from the concrete walls to improve the visibility of passing salmon.

The Locks took 5 ½ years to build and were dedicated on May 8, 1917.

Before that, a shipment of coal had to be transferred 11 times en route from mines to waterfront, said the Corps of Engineers. Logs were loaded on wagons and laboriously pulled over muddy roads.