Beauchastel is located some 10 km south by south-west ofValence and 20 km north-east ofPrivas. Access to the commune is by the D86 road fromCharmes-sur-Rhône in the north which passes through the commune and continues south toLa Voulte-sur-Rhône. The D86E branches from the D86 at the northern communal border and goes to the town then continues south to rejoin the D86 at La Voulte-sur-Rhône. The D21 goes west from the town toSaint-Laurent-du-Pape. The east of the commune includes a portion of theÎle Saint-Thimé in theRhône river which is also the departmental border withDrôme. A railway line fromSaint-Péray in the north to La Voulte-sur-Rhône in the south passes through the commune but there is no station in the commune. The commune consists of a large urban area along the banks of the Rhône with farmland south of the Eyrieux and forested hills for the rest.[6][7]
A branch of theRhône forms the eastern border of the commune with the main branch flowing south through the commune and continuing to eventually joining the sea atPort-Saint-Louis-du-Rhone. TheEyrieux river flows through the commune from the west to join the Rhône just south of the commune. Numerous streams rise in the commune and flow south to feed the Eyrieux including theRuiseeau de Thouac (which forms the western border of the commune), theRuisseau d'Abrou, and theRuisseau de Chauvert. TheRuisseau de Feuillas flows east through the north of the commune to join the Rhône. There is a dam on the main branch of the Rhône with an electricity generating station: theCentrale Electrique de Beauchastel.[6][7] Beauchastel was often the victim of floods of the Eyrieux, until the construction of a damin the upper reaches of the river in 1860.
The commune takes its name from the castle "Bel Castrum" built in the 12th century by the Lords of Retourtour and Briand. Since ravaged by theWars of religion, all that remains is the fortified tower that dominates the village.
In the 17th and 18th centuries Beauchastel was one of the Royal salt barns for the payment of theGabelle of salt.
TheBellum Castrum Medieval village. In 1179 the first lords, Retourtour and Briand, built a tower and ramparts to defend against invaders. The medieval village is built on the site of the old castle. During theWars of religion the village was destroyed in 1622 by order ofLouis XIII and the fortifications of Beauchastel were levelled; the ramparts and the defence towers disappeared. Despite these demolitions the site retained its medieval aspect enriched by architectural elements from the Renaissance until the early 20th century.
TheAncient Castle dating back to the 12th century overlooks the village. It was limited to a protectiveKeep with a square base of which only a section of wall remains. It was destroyed together with the village during the wars of religion.