The fortifications of such a purpose-built pā included palisades of hard puriri trunks sunk about 1.5m in the ground and split timber, with bundles of protective flax padding in the later gunfighter pā, the two lines of palisade covering a firing trench with individual pits, while more defenders could use the second palisade to fire over the heads of the first below. Simple communication trenches or tunnels were also built to connect the various parts, as found at Ohaeawai Pā or Ruapekapeka. The forts could even include underground bunkers, protected by a deep layer of earth over wooden beams, which sheltered the inhabitants during periods of heavy shelling by artillery. A limiting factor of the Māori fortifications that were not built as set pieces, however, was the need for the people inhabiting them to leave frequently to cultivate areas for food, or to gather it from the wilderness. Consequently, pā would often be seasonally abandoned for 4 to 6 months of each year. In Māori tradition a pā would also be abandoned if a chief was killed or if some calamity took place that a tohunga (witch doctor/shaman) had attributed to an evil spirit (atua). In the 1860s, Māori, though nominally Christian, still followed aspects of their tikanga at the same time. Normally, once the kūmara had been harvested in March–April and placed in storage the inhabitants could lead a more itinerant lifestyle, trading, or harvesting gathering other foodstuffs needed for winter but this did not stop war taking place outside this time frame if the desire for utu or payback was great. To Māori, summer was the normal fighting season and this put them at a huge disadvantage in conflicts with the British Army with its well-organized logistics train which could fight efficiently year round. Swamp pā Fox noted that lake pā were quite common inland in places such as the Waikato. Frequently they appear to have been constructed for whānau (extended family) size groups. The topography was often flat, although a headland or spur location was favoured. The lake frontage was usually protected with a single row of palisades but the landward boundary was protected by a double row. Mangakaware swamp pā, Waikato, had an area of about 3,400 m². There were 137 palisade post holes identified. The likely total number of posts was about 500. It contained eight buildings within the palisades, six of which have been