The Bridge of Sighs is a bridge in Venice, Italy. The enclosed bridge is made of white limestone, has windows with stone bars, passes over the Rio di Palazzo, and connects the New Prison to the interrogation rooms in the Doge’s Palace. It was designed by Antonio Contino, whose uncle Antonio da Ponte designed the Rialto Bridge, and it was built in 1600.

More details: https://en.wikipedia.org/wiki/Bridge_of_Sighs