My old house had one. It was an 1875 Victorian gothic farmhouse and while we were restoring it, I was always on the lookout for neat old stuff left behind by previous owners. All I found was a small silver letter opener and a couple of rusty nails.
In Turkey, a basement can hide more interesting things....like wellheads attached to a network of secret underground cisterns, teaming with carp. Not unusual for Istanbul, but even cisterns don't take the top spot of amazing basement artifacts.
I was reading my Hurriyet Daily News the other day and I came across this:
"The Roman-era city of Germenicia was unearthed by chance during an illegal excavation in the basement of a house."
OK. So what they really mean is someone noticed mosaics in their basement and they wanted to see what the rest of the pretty pictures looked like. A few eminent domain rulings later, and Turkey has another historic site to visit.
Mosaics found in SE Turkey lead to unearthing of ancient Roman city (hurriyetdailynews.com)
Germanicia Found? (rogueclassicism.com)