[Excerpt from a light historical overview of the architecture of Dunwall]
Across the generations, the aqueducts and tunnels beneath the City of Dunwall have served a variety of purposes.
In the earliest days of the city's history, several primary canals were used to channel river overflow during times of flooding. And for a time it was fashionable for wealthy aristocrats to commission underground water passages, giving them access to their estates from the Wrenhaven River and its minor tributaries. Over the years, these tunnels began to interconnect, sometimes by design and sometimes by accident.
The history of the tunnel system is rich. As every school child is taught, rebels used the sewers extensively during the Morley Insurrection. As discussed in popular bar songs, lovers often find privacy in some of the cleaner entry points, with fresh air brought in on the winds from the river itself. On a darker note, in addition to seeing traffic from gangs and smugglers, it is rumored that the current Royal Spymaster himself, Hiram Burrows, has a network of informants who know the twists and turns of the sewer system by heart.
Until recent times, the older tunnels suffered from repeated collapse, creating sinkholes that occasionally consumed entire street corners. The current system rarely suffers from such calamity, since the sewers were reinforced and expanded by the City Planning Department during the rule of Emperor Euhorn Kaldwin the First.