Construction crews have been finding some seriously cool stuff while digging out a new mouth for the Don River in Toronto's Port Lands, but all of those old shoes and newspaper clippings from the 1800s pale in comparison to Waterfront Toronto's latest discovery: Brand new, very old plants.

"Over 100 years ago, fill was dumped into the biggest marsh in the Great Lakes to make the Port Lands. Now, we're digging that up to recreate a natural, marshy mouth for the Don River — and we discovered something surprising," reads a new post on the $1.25 billion Port Lands Flood Protection project's website.

"Seeds from plants that would have been growing in Ashbridge's Bay Marsh 100 years ago!"

Tell me that isn't insane; The resilience. The mystery. The biochemistry. The magic...

Nature is so undeniably badass.

An exciting discovery in the Port Lands! These plants grew from seeds that had been buried deep underground for more than a century. https://t.co/18ZLu7uuIg pic.twitter.com/L2qekJW1vt

— Waterfront Toronto (@WaterfrontTO) April 21, 2022

It's been roughly five years since work began on what is being billed as "one of the largest waterfront revitalization projects in the world," and with every pound of soil removed Toronto comes one step closer to having a massive, brand new island with parks, housing, commercial and office space.

Villier's Island is expected to be complete by 2024, at which point the Don River will have been fully rerouted to protect the area from flooding (which is in fact the true impetus behind this massive undertaking.)

Progress on the river valley itself has been impressive, but excavating millions of cubic metres of old soil and gargbage takes time. While crews are working along at a clip, there's still dirt to remove and, apparently, treasures to uncover.

"In a low-lying section of the future river valley, construction crews noticed some unusual plants had sprung up out of nowhere. It's not uncommon to see plants on the site, but these plants caught their eye because they looked a lot like plants that grow in wetlands, not like the scrubby weeds that have popped up elsewhere," reads Waterfront Toronto's newest blog post, entitled "100-year-old seeds."

As it turns out, these plants were growing in an area that had been excavated about a year ago, some seven metres into the earth— deep enough to uncover the marsh's original soil without removing it.

"By chance, this area was relatively flat with poor drainage, and wasn't scheduled for further work for several months," reports Waterfront Toronto. "Over the summer the weather warmed up, water accumulated in the peaty soil, and more-than-century-old seeds sprang to life!"

Can you spot the modern weeds vs. bulrushes grown from century-old seeds? Our team got a great surprise when plants sprouted from a historical seedbank in the Port Lands. Read more: https://t.co/cirugNb76x pic.twitter.com/JQyrVW7CN2

— Waterfront Toronto (@WaterfrontTO) April 11, 2022

It didn't take long for specialists to realize that these plants had grown from the historic marshland soil. Waterfront Toronto immediately reached out to the Toronto and Region Conservation Authority to relocate these precious new old plants and harvest any possible remaining seeds.

"We were able to identify at least two species of leafy plants that grew. Hard Stem Bulrush and Cattails were growing well, so we transplanted them to Tommy Thompson Park nearby," notes the blog post.

"The team also collected around 50 buckets of the surrounding soil, in the hopes that more seeds and species might germinate. We hope to know the results later in 2022."

Experts say it's pretty rare to find living plants that were around more than 100 years ago, and many are interested in studying the seeds. Waterfront Toronto says that Tom Gludovacz, a horticulturist at U of T, is currently "overseeing the buckets of soil and conducting genetic tests on the plants."

"It's rare that you can compare a modern plant to a plant grown from pre-industrial seeds, so the discovery of these seeds was exciting," says Waterfront Toronto. "Only time will tell if plants adapted for the 1890s will be able to thrive in 2024 and beyond."