Jan van Eyck | Jan Matejko Academy of Fine Arts | Jan Hammer | Jan Peerce | Jan Hus | Jan Mayen | Jan Guillou | Jan Smuts | Jan Fabre | Jan Morris | Jan Matejko | Johann Nepomuk Hummel | Jan Garbarek | Ignacy Jan Paderewski | Jan van Riebeeck | Jan Troell | Jan Tinbergen | Jan Neruda | Jan-Michael Vincent | Jan Kochanowski | Jan Brewer | Jan Bechtum | Jan Zamoyski | Jan Ullrich | Jan Peter Balkenende | Jan Egeland | Robert Jan Stips | Mian Shakirullah Jan | Jan Weenix | Jan Timman |
The earliest roundel to be described was the one at Krpy (Kropáčova Vrutice), Bohemia, by Woldřich 1886, but it was only with systematic aerial survey in the 1980s and the 1990s that their ubiquity in the region became apparent.