The Maroa Caldera (Maroa volcanic centre, Maroa volcanic complex, Maroa dome complex) is approximately in size and is located in the north-east corner of the earlier Whakamaru caldera in the Taupà  Volcanic Zone in the North Island of New Zealand. Volcanic activity in the complex commenced over 300,000 years ago and the most recent volcanic eruption within it was 9,400 years BCE.
Its northern rim is to the south of the Waikato River at ÃÂtiamuri. At ÃÂtiamuri the Ohakuri Caldera which had a paired eruption with the Rotorua Caldera is to its immediate north. The eastern boundary is also defined by the present Waikato River and it extends as far south as probably opposite Orakei Korako on the river. The southern boundary is somewhat ill-defined given the subsequent deep deposits from the Taupà  Volcano but includes a number of domes of which the highest is Maroanui at .
The Maroa Caldera's last major eruption produced of tephra about 230,000 years ago (230 ka). Its earliest eruption was about 300 ka with decreasing frequency and volume to as recently as 11.3âÂÂñâÂÂ1.7 ka before present (BP), when an eruption of about occurred from the Puketarata volcanic complex ( to distinguish from another older volcano of this name near Te Kawa). The caldera is now mainly dome lava in filled. In summary going back in time: