The Temštica, known as the Topli Do river ("Toplodolska reka", Топлодолска река) in the northern part, originates from five streams from the Stara Planina mountain on the Serbian–Bulgarian border. Three major streams spring out from several peaks of Stara Planina: Midžor/Midzhur (Миџор/Миджур), Vražija Glava/Vrazha glava (Вражија Глава/Вража глава), Bratkova Strana (Браткова Страна) and Gola Glava (Гола Глава). They all join together near the village of Topli Dol, which gives the alternative name to the river. Temštica carved a canyon, popularly nicknamed "Little Colorado". The river continues to the northwest and receives the Visočica from the left.