Thanks for the background. I guess this is similar case to some suites in One Wall Centre with nobody seeming to know if the owners even remember owning such property. I kid you not, there were few suites that neither the concierge or the rental agent seemed to have any idea what's the deal is and how the owner could be contacted.
Some people have so much money that it's just not worth their time to care about sums of money leaving or entering their account, be it in tens of thousands. Few years ago there was a news story of a rich French lady being hustled hundreds of thousands of Euros by his toyboy for years. Once he was finally caught, the lady told people that she couldn't notice amounts as small as 50k Euros go missing from her account!
I also hope the site gets developed as currently it's the owner losing out on it. The lot is today probably 500 times its original value, but that is only theoretical as long as you don't sell it. Currently the city is benefitting greatly from the property tax flowing in.
Strange case overall, but if there are two positives to it, it is that at least it is not a fenced-off dead zone and at least there is that nice huge tree.