The Skopje Aqueduct is the only aqueduct in Macedonia, and one of three largest and well preserved in the former Yugoslavia.
The question of when the Skopje Aqueduct was built is unclear. There are three theories, it may have been built during the reign of Rome (1st century), during the reign of Byzantine Empire (reign of Emperor Justinian I) or during the reign of Ottoman Empire. According to this latest theory the aqueduct was built in the 16th century for the many Turkish public hamams.
This aqueduct was in use until the eighteenth century. Only about 386 meters with 55 arches of this structure of stone and brick remain.
References:The Citadelle of Quebec is an active military installation and official residence of both the Canadian monarch and the Governor General of Canada. It is located atop Cap Diamant, adjoining the Plains of Abraham in Quebec City. The citadel is the oldest military building in Canada, and forms part of the fortifications of Quebec City, which is one of only two cities in North America still surrounded by fortifications, the other being Campeche, Mexico.
The first fortifications in Quebec were built by the Governor General of New France Louis de Buade, and completed just in time for the Battle of Quebec in 1690.
After the British conquest in the second half of the 18th century, the problem of Quebec City's defences grew more acute.