Original: The current provinces of Cienfuegos, Sancti Spíritus, and Villa Clara were once all part of the now defunct province of Las Villas, but Villa Clara is still referred some times just as "Las Villas" using the shorter old name.
Simplified: The provinces of Cienfuegos, Sancti Spíritus, and Villa Clara were once all part of the now defunct province of Las Villas.