Sydney Opera House
Because of it's cutting edge design at the time, the project was plaqued with construction difficulties and cost over-runs. Due to his disagreements with the project team, Jorn Utzon actually walked off the project before it was completed. Fortunately the project was finally completed in 1973, more then 10 years after it was started. The final cost was AUD 102 mil., a small amount by today's mega-obsessed standards, but an enormous budget for a public building at the time.
The Sydney Opera house is now listed as a UNESCO World Heritage Site in recognition of it's cultural significance and universal values.