This Traveltalks entry concentrates on Holland's historical relationship with its main industry: growing tulips. The country's windmills are also highlighted.This Traveltalks entry concentrates on Holland's historical relationship with its main industry: growing tulips. The country's windmills are also highlighted.This Traveltalks entry concentrates on Holland's historical relationship with its main industry: growing tulips. The country's windmills are also highlighted.