These beautiful flowers are water lilies or Nymphaeaceae. Here is a general description of the family.
Nymphaeaceae /ˌnɪmfiːˈeɪsiː/ is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world. The family contains five genera with about 70 known species. Water lilies are rooted in soil in bodies of water, with leaves and flowers floating on or emergent from the surface. The leaves are round, with a radial notch in Nymphaea and Nuphar, but fully circular in Victoria and Euryale.