A pleasant place to spend a day. The ArslanTepe archeological site is fantastic.
The history of Erzurum Castle dates back to about 2,500 years ago, to the Urartians, who dominated the region. The first version of the inner castle, which still exists today, was built by the Byzantine Emperor Theodosius in 415. The ancient tombs and mosques are quite interesting.
A nice city — the Süleymaniye Mahallesi is quite historic with many old buildings — some of which are being restored. It is said to date back to 3,000 BC.