and relocated. In 1942, during the Nazi German occupation of Denmark in World War II, the old Lego factory was destroyed by fire, but a new one was immediately erected. In 1946, the railway track from Grindsted was extended to the Lego factory. In the same year, the Lego company purchased a plastic moulding machine from an English company. Plastic Lego bricks were first released from the factory in 1949 and near the end of the 1950s wooden toys had fallen out of favour. The 1950s brought a recession to Billund with the closing of the railroad. In response to the growing poverty, the Billund Housing Association was founded and created affordable housing as well as a retirement home. Lego created a large park north of town with a playground, outdoor scene, toboggan hill and a man-made lake in 1959. In 1964 the Billund Airport was inaugurated, first as the Lego Group's private airport, and was later opened for other uses. Legoland Billund opened on 7 June 1968 and received 3,000 visitors on its opening day and 625,000 in its first year. It was the only Legoland until 1996, when other Legoland theme parks were built in Carlsbad, California, and Günzburg, Germany. Billund again began to experience growth. In 2010, a partnership of organisations that began with the Lego Foundation and the municipal government founded the Capital of Children, which provides opportunities for children to participate in community projects and holds an annual Children's General Assembly. In 2020, Billund was the first town in Denmark to be designated as a UNICEF Child Friendly City, which demonstrates a commitment to the UN Convention on the Rights of the Child. Geography Billund is located approximately from Grindsted, from Esbjerg, and from The Regional Capital of Vejle. Billund Brook runs through the centre of Billund, starting as a small ditch in the westernmost side of Randbøl parish, and continuing west to Grindsted and Varde. The local terrain is mainly flat with sandy soil. To the south-west of Billund is Grene Sand, where inland sand dunes deposited sand onto nearby fields in stormy weather, requiring hedgerows to be planted. Local bogs were used to obtain peat as a source of fuel from ancient times. Local farmers practised heath farming, growing rye to produce bread. To the east and north of Billund, the moors fed large flocks of sheep, which were under attack from wolves,