Qohor is one of the nine Free Cities in western Essos, located between the Narrow Sea and the grass plains held by the Dothraki. It is located several weeks' ride east of Pentos on the western edge of the vast Forest of Qohor.
The khalasar of Khal Drogo passes close to Qohor during their journey to Vaes Dothrak. Ser Jorah Mormont takes advantage of their proximity to procure more supplies, but in reality, to also send word to Varys that Daenerys Targaryen is pregnant.
In the books
In the A Song of Ice and Fire novels, Qohor lies east of Pentos and Norvos, close to the edge of the Dothraki Sea and in a vast area of woodland and grassland known as the Forest of Qohor. The city is also located on the River Qhoyne, a tributary of the vast Rhoyne, and Qohorik warships control the territory south to Dagger Lake.
Its proximity would make it vulnerable to Dothraki attack, and shortly after the fall of Valyria (of which empire Qohor was an outpost) the Dothraki indeed attempted to sack it. However, the governor purchased three thousand Unsullied, warrior-eunuchs from Astapor in Slaver's Bay, to help bolster the garrison. The Dothraki lost thousands upon thousands of men and horses upon the Unsullied shield-wall, including their khal and most of his bloodriders. Though they reduced the Unsullied to a handful of men, the remaining Dothraki honored their achievement and spared the city. Since that time Qohor has been guarded by an Unsullied garrison and the Dothraki have not attempted to attack it again.
Qohor is famed for its blacksmiths, craftsmen and metal-workers. Its citizens worship a deity known as the Black Goat.
"Qohor" is pronounced "Kwoh-hor", as opposed to "koh-hor" (Jorah pronounces it "kwoh-hor": if it was "koh-hor" it would have just been spelled "Kohor" with a "K").
Qohor is shown in the incorrect location on the Season 2 Viewer's Guide map. This map has Qohor north-west of its proper location, on the wrong tributary of the Rhoyne (and much further away from the Forest of Qohor). However, the "Areas of Control" map for Season 2 puts Qohor in its correct location, matching that of the novels.