In 1708 architect Sir John Vanbrugh designed and executed an ambitious plan. He wanted to develop a “habitable viaduct” on the grounds of Blenheim and finished construction in 1710. This is known as the Grand Bridge, or Vanbrugh Bridge, the site of the modern restoration work. However, not everyone was so keen on the architect’s ideas.
Sarah, First Duchess of Marlborough, was not impressed with Vanbrugh, for example. She found his plans a little too ambitious and expensive, and so Vanbrugh was banned from Blenheim. But the Grand Bridge still stands as a testament to his ideas.
However, the Grand Bridge did not remain as Vanbrugh built it. In fact, the inside was flooded in 1768 as part of gardener and architect Lancelot “Capability” Brown’s project to bring a 160-acre set of lakes to the grounds. And the inside of the bridge has not been exposed since then.