Information required on Ghar Lapsi building

When driving down to Ghar Lapsi I have always been intrigued by the apparently derelict, Gothic-style building on the slopes behind the restaurant. I have asked a number of people for information about it but have always drawn a blank.

My curiosity was recently further aroused when I realised that next to the window in the tower of the building, is a roundel with a motto underneath which reads 'Qvasi oliva speciosa in campis'. A search on the internet gave the following result: an identical motto is found on a painting, Madonna dell'Ulivo, by Pietro Antonio Ferro (1611) in the church of Santa Chiara in the township of Tricarico, province of Matera.

In the painting the motto is displayed on a scroll flowing from an olive branch. This is, quite possibly, just a coincidence and the Lapsi motto might have a different origin. I wonder if any of your readers can provide information about the date of the building, a translation of the motto and the connection, if any, between the building and the town of Tricarico.