Whether it's an inconvenient watermark, crop mark, or some other type of special mark, you may find that at some point, you need to remove special marks from a PDF document. Since PDF documents are ...

Crop marks are the shapes and outlines of archaeological features and structures created by the varying growth heights of the crop being grown over the area. A lot of archaeological sites have been ...

A recent heatwave in the U.K. has revealed outlines of ancient structures previously unknown to archaeologists. NPR's Renee Montagne asks aerial archaeologist Toby Driver what he's been learning. And ...

ABERYSTWYTH, WALES—BBC News reports that an ongoing heat wave in Britain has resulted in the emergence of crop marks across Wales. Crop marks form when dry conditions parch the landscape, but some ...

The remains of this medieval castle at Castell Llwyn Gwinau, Tregaron, were almost completely plowed over, but they show clearly under parched conditions. Royal Commission on the Ancient and ...

Ars Technica has been separating the signal from the noise for over 25 years. With our unique combination of technical savvy and wide-ranging interest in the technological arts and sciences, Ars is ...