The highest-assessed parcels in Philadelphia County, PA, ranked by market value from the county's own roll. This county records values for most of its parcels, which is what makes the ranking honest.
Ranking is by assessed value; where an acreage below comes from the parcel's mapped boundary rather than the county's roll, it is marked † below. That is a close match for deeded acreage — the median of the two agrees where counties publish both — but it is not the deed, and it will differ where a deed runs to the centreline of a road or where several units share one footprint.