Complex sentence: The Trust's headquarters are in Number One Royal Crescent, Bath; built by John D Wood is the cornerstone of one of the most significant urbam architectural achievements of the 18th century and represents the highest point of Palladian architecture in Bath.
Split into simpler sentences: The Trust's headquarters are in Number One Royal Crescent, which was built by John D Wood. It is the cornerstone of one of the most significant urban architectural achievements of the 18th century and represents the highest point of Palladian architecture in Bath.