Can’t imagine there’s a lot left after 100 years.
You’d be surprised. Many years ago I worked on a site (housing) in Bethnal Green, iirc it had been a large garage/car dealership, but unknown to everyone it had previously been the site of a Victorian Workhouse. The Workhouse had buried its dead in its own grounds and when the diggers started to do their business, they unearthed countless graves.
Pretty much all the skeletons and coffins were intact and ended up strewn all over the site, even though the coffins were unsurprisingly just cheap things made of planks – tragically many were tiny ones for children.
At that time there were many Irish catholic building workers, and they got really spooked up and angry about the affair, and the press were called. As the graves were over 100 years old it was all legal, so just as a mark of respect the contractor had all the bones and bits of coffins collected and burnt in a heap – the sight of people’s skeletal arms or legs sticking out of the muck away lorries as they left the site and drove through London hadn’t been very pleasant.
I also remember the young plumbing apprentices perched like vultures on the scaffolding, waiting to swoop if the diggers unearthed an ‘interesting’ bone or piece of coffin – gruesome !