The first White Town on the route proper is CASTELLAR DE LA FRONTERA , 27km north from Algeciras, a bizarre village within a thirteenth-century castle, whose population, in accord with some grandiose scheme, was moved downriver in 1971 to the "new" town of Nuevo Castellar, whose modern square frames an image of their former castle home on the hill behind. The relocation was subsequently dropped and a few villagers moved back to their old houses, but most of them were taken over by retired hippies (mainly German, mainly affluent). The result didn't entirely work, with suspicion from the locals and hostile exclusivity from some of the new arrivals fuelling tensions which remain today. Recent plans to rebuild the castle as a tourist centre - complete with parador - appear to have ground to a halt.
The only places to stay inside the castle walls are Casas Rurales Castillo (tel 956 236 620, www.cadiz.org/tugasa ; ( Euros48-60) which consists of a number of restored village houses, or the Posada Antigua (tel 956 236 101; ( Euros18-27), with two en-suite rooms; Hostal El Pilar c/León Esquivel 4 (tel 956 693 022; ( Euros18-27), lies below in the dull new town. There's a bar near the entrance to the castle and within the walls El Aljibe is a decent traditional restaurant attached to the Casas Rurales accommodation (above); an average venta at the start of the climb to the village on the main A369 is the only other food option, otherwise there's not a lot more to detain you.
Video of Castellar de la Frontera