Cahors is built in a loop or meander of the Lot River, called a boucle in French (boucle = curl or buckle). The city was a prosperous commercial and educational center in the middle ages, and the Knights Templar established themselves there for a while.
The city's most famous monument is probably the Pont Valentré, a fourteenth century towered bridge with a legendary history. I posted a brief résumé of the legend here, along with a better photo of the bridge that I took in 1989.
Cahors is also famous for something else: its red wine. The Romans brought wine grapes to the Quercy region over two thousand years ago. Later, in the middle ages, Eleanor of Aquitane and Henry II Plantagenet favored Cahors wine in their court. The English, apparently, dubbed the wine "black" due to its dark color and rich taste.
The primary varietal in Cahors is côt noir, also called auxerrois. The same grape is known as malbec in Bordeaux and simply côt here in the Touraine region. A.O.C. wines in Cahors must contain at least seventy percent côt.
You can find Cahors in many wine shops in the USA. I like it, and if you like tannic reds, you might, too.