Billund is a small 'village' with not much there other than Legoland. It is a great little place, and the people are friendly and helpful, but there's not much to do. There is also Lalandia which is a great family day out with a swimming pool complex, mini golf, tenpin bowling and restaurants etc. But don't expect much else in Billund except Legoland and Lalandia. It depends how much time you want to spend there - or how long your family days out with the kids are at Legoland, but you can probably happily cover Billund in a 2day weekend.