Completed in 1884, the neo-Renaissance opera is impressive enough on the outside. But its interior is the part that's breathtaking - gilt and marble, with lavish and intricate frescos. The auditorium was designed by eminent architect Miklós Ybl and decorated by some of the most distinguished painters of the age. If you're coming to see the building, and not an opera, take the tour: head for the right-hand entrance near the buxom sphinx.