A team of workers at a downtown Calgary construction site discovered a little bit of Canada’s history during excavation last week.

ENMAX workers, who have been working on a major upgrade to a downtown substation, halted their activities when the found a number of artifacts dating back to the 1880s.

Experts say the substation was located on where the Canadian Pacific railway had their original rail lines, so the discovery is considered to be significant.

The items found include pickaxe heads, rail spikes, a brick, window glass, clinker (a waste material during smelting), also with various other items.

Initial investigation has dated the artifact as being from the late 19th or early 20th century, but further examination will be done to determine the exact age.

“Significant historical items can often be found in old areas of major cities,” said Michelle Wickham, Senior Project Archeologist and Partner, Bison Historical Services Ltd. in a release. “Unfortunately, when items are discovered, they are not always handled as they should be, leading to either damage or total loss altogether. We commend ENMAX for preserving Calgary’s historical record in this way.”

The excavation of the items was accomplished using special equipment and procedures.

A professional archaeologist has been called to the construction site to monitor the rest of the upgrading work.