All tracks are steep and can get slippery when wet. A sign at the park warns users to take extreme care.
Family friend Rochelle Bullock spoke to the Chronicle on the family's behalf.
"I saw him just before he went out for his ride. He was so looking forward to 2017 and celebrating the new year with friends. He was like a brother to me," Ms Bullock said.
"He was wearing his taonga, pounamu."
Dr Cresswell was passionate about equality, the environment and medicine.
Ms Bullock said Dr Cresswell was "well respected and loved amongst all people."
He worked alongside iwi and was prominent in advancing Maori health.
He was also politically active and a member of the Green Party. He was a major player in raising awareness of climate change, and publicly opposed and demonstrated against the Trans Pacific Partnership and seabed mining.
In September last year he climbed on top of local MP Chester Borrows' car during a protest against the TPP and in November helped organise a local march to encourage awareness of climate change issues.
Dr Cresswell was well known to Chronicle readers for which he wrote a regular column.
A police spokeswoman said the death was being treated as a sudden death and was not thought to be suspicious.
Funeral service details will be available after Wednesday, Ms Bullock said.
Dr Cresswell was the Whanganui branch president of the Association of Salaried Medical Specialists.
Members were saddened by news of his death, said the association's executive director, Ian Powell.
"Dr Cresswell was a highly passionate and compassionate doctor, full of exuberance. While concern for the patients he treated was central to his work, he also saw the role of the doctor extending into broader issues, including the effects of environmental and trade policies on people's health and well-being.
"This involvement in broader issues also required courage, a personal quality he had an abundance of.
"Our thoughts are for his family and close friends at this sad and difficult time."
