@Tsedey B. - Are you spending some time in Puerto Rico? I live in the San Juan area and agree there are a ton of abandoned properties all over the island. The municipalities here began a new program in November 2020 to eminent domain blighted/abandoned properties and sell them. There is a court process they go through which does take some time (6 months). It just started, and there's a lot of properties ! I'm involved in the program restoring some of these properties once they have gone through the process. I am still learning more about it and will have more answers over the next couple weeks/months. The properties I am seeing have been abandoned 10 years or more, but many still have good structure. As for other properties, you can use websites showing tax records here https://www.crimpr.net/ and perhaps use skip tracing services like TLO to find owners. (I haven't done this personally). Like you, I see the opportunity here.