Designed by William Wardell, Melbourne's Catholic cathedral is among the world's finest examples of Gothic Revival architecture and the largest church building in Australia. Building began in 1858 and continued until the spires were added in 1939. The imposing bluestone exterior and grounds are but a preview of its contents: inside are several tonnes of bells, an organ with 4500 pipes, ornate stained-glass windows, and exquisite mosaics in the Blessed Sacrament chapel.