The River Poddle was covered up a long time ago. The fact that the rive runs under the Olympia Theatre and under Dublin Castle gives you an idea of the tunnel's age.
The wide streets of Cork are actually covered over rivers… Are there any photographs of this aspect of Hidden Cork?
River Poddle underneath the city of Dublin's streets
Pictures of Dublin's River Poddle underground, making its way underneath Temple Bar in culverts built during the medieval period; these exclusive pictures were taken by an insider.