The steep slopes of 232m-high Mauao swarm with walkers in the morning, when the Mount’s early risers perform their ritual climb to the summit. The ascent is signposted to take an hour, though you’ll see people striding up it in less than 30 minutes (and often running down). The gentler 3.5km loop around the base should take around 45 minutes.
If you just want a view of Mauao, wander across the causeway to Moturiki (Leisure Island), which peers along Main Beach to the extinct volcanic cone.