The ancient walls around Quebec City are being torn down this summer, but the historic site isn't being destroyed.

Like everything built in this province the centuries-old walls are in need of restoration and renovation in order to be preserved for the years to come.

"It looks very intrusive. It's an impressive work, but it's a necessary work if we want to give a legacy to the next generations," said Jo-Anick Proulx of Parks Canada.

Sections of the wall have been rebuilt many times since the original 17th century construction, with the St. Louis Gate being rebuilt at least three times in centuries past.

The cold winters of Quebec take their toll on the walls, and Parks Canada asset manager Louis Michel said every few decades, construction crews have to dig in.

"What we see here today at the St. Louis Bastion dates back to 1750," said Michel.

"We conduct surveys yearly and a big one every five years and this one had been identified as an area where we needed to come in and do major restoration work."

Parks Canada has done work on the wall before.

"Throughout the years, the walls have been maintained in good shape. Parks Canada did some work in the '70s and 1980s," said Proulx.

This summer each stone from the St. Louis Gate will be pried out of place and numbered, with its location marked.

Those that are still in good shape will be re-used, while others will be replaced.

"The masons will remove the stones and the ones that have been identifed obviously to be changed we will replace them with the same type of sandstone with the exact same dimensions," said Michel.

Archeologists and architects are overseeing the work, which is expected to take two years.

"The goal is to preserve as much as we can and reassemble afterwards the wall the same way as it was done originally," said Michel.

Until then, the sections of the wall will be like all other construction projects in Quebec: off-limits to the public until complete.