Aqueducts have been known since Roman times and are bridges with which convey water across a valley or other gap including other waterways. A particularly spectacular aqueduct is located in County Wiltshire near the town of Bradford-on-Avon: The Kennet & Avon Canal coming from Bath turns in a sharp right turn on to the Avoncliff Aqueduct and first of all crosses the two-track railway line Bath-Westbury (there is an exit to a Avoncliff station from one of the Aquaeduct sides). It then crosses the River Avon, which flows in the valley below. After another narrow left turn, the canal turns east again towards Bradford-on-Avon.
A good description of the above can be seen in this PDF of the Canal & River Trust. Incidentally; squeezed between the river and canal, on the southern bank of the River Avon on the hillside is the “Cross Guns” pub located, where you can sit and relax in the pleasant atmosphere of its terraced garden.