St Colman's is the Catholic cathedral of the Diocese of Cloyne, and it dominates Cobh from every angle. Built on a terrace high above the harbour, the neo-Gothic church took more than half a century to finish: work started in 1868, the plans were revised and costs rose, and it was only completed in 1919. Its 91.4-metre spire makes it the tallest church in Ireland.
Inside, the scale is just as impressive, and the cathedral has a 47-bell carillon whose largest bell weighs 3.44 tonnes. It's open daily and entry is by donation. Walk round to West View on its western side for the classic photo of the spire rising over the coloured houses.