The Silver City is the capital of the High Heavens.
The Silver City is like a small world unto itself, a sprawling complex of glittering, soaring spires and sweeping buttresses. Its architecture pulses with light, and it sits in a backdrop of radiant luminescence. True to the nature of Heaven, where its domains are set, it is said that the Silver City is forever, that it will never change. Its tallest tower, the Silver Spire, contains the Crystal Arch, the supposed birthplace of all angels.
The city was protected by the Diamond Gates, and while they were assailed many times over the course of the Great Conflict, no demon ever gained entry to the city itself. No demon, that is, until Diablo invaded the city, the Lord of Terror now the Prime Evil, having combined the essences of his six counterparts into a single being. The gates were shattered and Hell gained access to the city. The forces of Heaven fought against the demonic hordes, but they were fighting a losing battle. Thanks to the efforts of Tyrael and a band of mortal heroes however, the city was saved and Diablo himself cast down. The damage to the city was 'healed' by light streaming from the sky above.