Floating platform in Peru

Some Peruvian indigenous people actually live on man made floating islands (on lakes, not at sea).

Perelandra!
I read Out Of The Silent Planet and Perelandra as a boy, enjoyed them.

But I couldn't make it through That Hideous Strength, I put it down baffled and bored one day, and never picked it up again. Now I'm thinking I was too young for it, particularly growing up so far away from the novel's setting in England.

The first two novels take place in Mars and Venus, so there's a sense of adventure. But in That Hideous Strength, the mannerisms and situations and dialogue styles are akin to something like Brideshead Revisited in Oxford and/or Cambridge.

While a British boy might get the whole thing intuitively, I grew up in Mexico, so had no mental compass of that world at that age. It was all as confusing to me then as God Emperor Of Dune was later.