Sanctuary

The religious centre of your infrastructure. It researches not just Religion and Tax, as in vanilla RoN, but also serves to increase Attrition damage too.

In addition, as in Warbirth and Rise of the Moderns, it also trains mercenaries and units. Some are quite weak like European mercenaries, others are quirky but funtional (ie, Jungle Hunters) - but others like the Norse can train some pretty powerful units in here.