This is a video about a barn swallow nest.
According to Dutch TV programme Vroege Vogels, barn swallows are nesting on the ferry to Tiengemeten island. They have been doing so for four years now. Even though the ferry boat moves from or to the island two times an hour, the nesting is succesful.
Other swallows are said to have nested on moving trains.
And there seems to have been a jackdaw nest on the ferry to Texel island.