The Roman Catholic cathedral, completed in 1882 in Early English Gothic style by architect Joseph Hansom (the inventor of the hansom cab). It was the first new Catholic cathedral built in southern England since the Reformation.
The interior is unexpectedly large for a city-centre church and surprisingly little known to visitors who don't seek it out. Look up at the timber roof and at the modern stained glass in the south transept. Free entry; usually open during the day.