The lighthouses were unveiled at Market Hall, Devonport, before being put in place around Plymouth.
Alice Nimmo, a University of Plymouth illustration graduate, whose mother was cared for by St Luke’s, said she rooted her design in the “timeless nature of care-giving” and an inspirational trip to see the friezes of Pompeii.
She said: “I really want to pay tribute to what St Luke’s does for patients and their families. That very human care means a lot.”
For her lighthouse, Mrs Murals, aka Ellie Johnson, took a deep dive into the vulnerable local marine life.
She said: “My lighthouse is a celebration of Plymouth Sound and all we have in terms of biodiversity.
“But I have also included some man-made objects, such as ghost nets and a tyre, to emphasise the importance of protecting nature from human interference.”
She added: “It’s great to create something so large and impactful alongside so many really incredible artists.”
The Guiding Lights trail follows the Elmer trail which involved a parade of colourful elephants supporting St Luke’s in 2019.