The Aqua Marcia is one of the longest of the eleven aqueducts that supplied the city of Rome. The aqueduct was built between 144–140 BC, during the Roman Republic. The still-functioning Acqua Felice from 1586 runs on long stretches along the route of the Aqua Marcia.
Together with the Aqua Anio Vetus, Aqua Anio Novus and Aqua Claudia, it is regarded as one of the 'four great aqueducts of Rome.'
It was the first to enter Rome on arches, which were used for the last 11 km, and which were also used later combined with the Aqua Tepula and Aqua Julia.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.