Dien Bien Phu town it is still a place, where you will not see to many foreign tourist, like in another places, eg. Sapa, Ha Long Bay or Hanoi. Dien Bien Phu (20 km from Laos) is a place, where French troops suffered a big defeat by Vietminh in the Indochina war in 1954.
Muong Thanh valley in whole area of the town of Dien Bien Phu is a place of the biggest rice field in northwestern Vietnam after the Muong Lo area in Nghia Lo town (Yen Bai province). You will see there a lot of Thai ethnic villages with the typical wooden stilt houses. I recommend for exploring this area and for the whole province of Dien Bien to rent a motorbike.