San Giovanni al Castello della Tenuta dei Massimi is an 19th century farmstead chapel, apparently now deconsecrated, at Castello della Tenuta dei Massimi. This has a postal address of Via Portuense 882 in theMagliana Vecchia zone, but is up a long gated driveway.
The dedication is (apparently) to St John the Baptist .
The Tenuta dei Massimi is a large surviving country estate in the Roman Campagna, which escaped suburban development and is now administered as a nature reserve.
The farmsted consists of a large 19th century four-storey block with a belvedere tower, and a two-storey block attached to its north end. The chapel is apparently in the latter, although a simple bell-cote or campanile sits on the south gable of the main block. This has lost its bell.