The abandoned buildings before the blaze. Photo: Google Maps (file)
The abandoned hospital and former Kotuku Hostel was consumed in a massive fire on 10 August.
A 42-year-old Hoktika woman was arrested on Wednesday.
She faces a charge of arson and has been bailed to reappear at the Greymouth District Court on 24 September.
Seaview has been a prison, a home for people who were mentally unwell and a backpackers in the past.
The hospital was closed in the early 2000's, with only a handful of patients left to transfer elsewhere.
