It reminds me a lot of Founders Park https://www.founderspark.co.nz/ - which is only about 3km from where I work.
I find it quite theraputic to be able to walk around parts of history like this - thinking about "how things used to be".
This is a small local museum. Head east for about 20km and you get to Upper Canada Village, which is a large and well established site. Important buildings located in the areas affected by the flooding of the St Lawrence River were moved here. There are over 40 buildings, including a working flour mill and saw mill on a property that is about 25 hectares.
Another interesting thing that happened in this period is that buildings that were not considered to be worth saving were burned down by scientists from the National Research Council of Canada and the findings were incorporated into the National Building code fire safety standards.
https://www.uppercanadavillage.com/
Manfred, we have something similar in Banff NP. The construction of a hydro dam flooded a valley submerging a small town. Very popular dive site these days but the water is frigid...
https://www.banffjaspercollection.co...ke-minnewanka/
That reminds me of some of the dive sites in the St Lawrence River; the foundations of the old generating station (complete with exhaust tubes) and the submerged locks of the old Gallop canal and of course all of the ship wrecks. The river can get quite warm by the end of the summer. Lake Ontario shipwrecks were something I generally always dove in a dry suit (there were often a couple of thermoclines that helped make things uncomfortable in a 5mm wet suit.. I remember diving on a bridge that was submerged when they created a reservoir for one of the dams on the Madawaska River.
I never did any underwater photography. I tended to lose things on dives and a camera and housing were things I definitely wanted to come back to shore with.
Unfortunately the visibility was generally not great...
I got Chat GPT to do some research on the topic - this is part of it:
"By the 1990s, only a handful of road–rail bridges were still in service on the South Island. In fact, New Zealand’s last few dual-use bridges survived into the 2000s, mainly in low-traffic areas. The Awatere Bridge at Seddon continued to carry State Hwy 1 traffic until 2007, when its new replacement road bridge opened.
The old Awatere double-decker bridge is now rail-only, its century-old road deck closed off.
On the West Coast, the old Arahura Bridge (Hokitika) was replaced in 2009 by a new bridge that still carries both road and rail but with separate parallel decks (meaning cars and trains no longer share the same lane).
Finally, the historic Taramakau Bridge – often cited as the last true road–rail bridge in New Zealand – was closed to road traffic in July 2018. A modern two-lane highway bridge was built alongside it, leaving the 1893 Taramakau structure to be used only by trains (and cyclists/pedestrians) going forward.
This marked the end of an era: after 2018, no public roads in New Zealand share a single-lane bridge with trains anymore."
Personally, I haven't spent a lot of time travelling beyond my little part of the South Island as an adult; I possibly travelled over a few of them as a yongster with my parents back in the 60's, but I don't remember them. The only one I do remember is the "double decker" one in Seddon.