Roskilde Cathedral

Roskilde Cathedral in Denmark is a UNESCO World Heritage Site because it was the first Gothic cathedral to have been built with brick, and as a result the style spread to the rest of northern Europe.It dates from the 12th century thought there was an earlier wooden church in the 10th century.  Very early in the 11th century a stone (travertine) cathedral was built to replace the church.

During the next century the brick cathedral was built around the travertine building.  This allowed services to continue during construction.  When this was far enough advanced to allow services in the new building, the original cathedral was dismantled.