English: Borgund Stave church, about 800 years old and made entirely of wood. It's located near Lærdal and to get it you have to pass through the world's longest road-tunnel.It looks deceptively large, it's actually quite small and the entrance only fits one person.The construction is resilient thanks to the wood treatment: A tall tree would be found, its branches cut and the tree would start emitting sap. The sap covered the tree and they'd leave the tree alone for 5-20 years. That wood which had then 'self preserved' was used in this kind of construction. The base of the church sits on stone, so no ground moisture seeps upwards and the climate is generally pretty favorable with low humidity. So with these factors the church hasn't rotted away.There used to be hundreds of these across Norway but now only 20-30 remain.