Grand Bridge, Blenheim, from 'Fair Rosamund's Well'
Vanbrugh designed this bridge as an integral part of the Palace, however it was the cause of much argument between Vanbrugh and Sarah, the first Duchess of Marlborough. Vanbrugh intended something grander still, and also wanted rooms in the Bridge. Sarah thought it was unjustified extravagance (a relative term to be sure at Blenheim!), and stopped work before it was completed. The original plans survive, and I would say that Sarah was right.
The bridge didn't really have anything to cross until 50 years after it was built when the landscape gardener 'Capability Brown' flooded the area to make the lake, thus giving us essentially the Blenheim we know today.