Yverdon-les-Bains is; 2,821 children.6 of the population are between 0 and 9 years old and 3,041 teenagers.4 are between 10 and. The Municipality repurchased the spa, including the neighbouring Château d'Entremonts. The obligatory lower secondary school program lasts for six years and there were 1,410 students in those schools. The sulphur springs were already used for a thermal spa, as attested by excavations. Its spire had been rebuilt in 1608, on the base of the original one, for which huge, sculpted blocks from the ruins of the Roman "Castrum" had been used. 24 Transportation edit The narrow gauge electric YverdonSte-Croix railway line connects Yverdon to Sainte Croix. It has changed at a rate of 14 due to migration and at a rate.9 due to births and deaths.