The pale turquoise Nikolsky Sobor, with its gold onion domes, stands out west of the centre near the corner of Qabanbay Batyr and Baytursynuly. The cathedral was built in 1909 and later used as a stable for Bolshevik cavalry, before reopening about 1980. It's a terrifically atmospheric place, like a corner of old Russia, with icons, candles and restored frescoes inside and black-clad old supplicants outside.
For the best impression visit at festival times such as Orthodox Christmas Day (7 January) or Easter for the midnight services.