Launched in 2013, ISTRIA 100 by UTMB now attracts over 2,500 runners from around the world. Spanning five distances – 100 miles, 110 km, 69 km, 42 km, and 21 km – the routes showcase the full diversity of Istria: rugged, technical terrain, a touch of coastline, ancient medieval towns, deep forests, lively city centers, muddy valleys, streams and rivers, canyons, and countless breathtaking vistas.