Cidade de Goias is a tiny mining town and the former capital of the state of Goias.  The town really doesn't warrant more than a one day visit.  You can do a nice walk through the old colonial part of town walking up cobblestone streets to the Governor's palace (Palacio Conde dos Arcos).  And if you like sweets - this town in your happy place!    

I visited from the nearby town Goiania which is a quick 30 minute flight from Brasilia.  I rented a car for the easy 2 hour drive to Goias then retraced my steps to Brasilia that night.  It is nice to have a car because the surrounding area is very scenic, especially along the Rio Vermelho.  There is no obvious remaining evidence of the gold mining for which the town was founded in the early 18th century. 

The only reason that I can think that Goias was graced with the World Heritage designation over some others is that the colonial area remains in good shape - primarily because the town has really been left behind by Goiania.