Some regions of southwest France are relatively unknown but are worth discovering. The area (including Aveyron and Lot) has a hilly and green countryside with charming medieval villages some built on top of rocky promontories (Conques, Saint-Cirq Lapopie, Rocamadour), some in valleys (Estaing). Stunning man-made structures such as the Millau Viaduct (built in 2004) stand alongside extraordinary natural sites such as chasms (Padirac) and caves. Some caves have a worldwide reputation: the cheese caves of Roquefort-sur-Soulzon where the famous cheese was created and is still made today. Medieval gems such as the historic towns of Cahors and Albi are charming with their narrow medieval streets, half-timbered houses and local markets. Nature lovers will enjoy the gorges of the Tarn River.