Peter Crossley has dedicated 50 years of his life documenting over 200 lava caves beneath New Zealand’s largest city. As he pops manholes and digs up school playgrounds to find these caves, he muses on the unique history they offer—some have been used as wine cellars, others as burial grounds. He also realises that these ancient caves will be a casualty of inevitable urban growth. This film could be the last opportunity for audiences to experience these caves, in Crossley’s words, “before they go”.