'Seclude' is Latin for 'shut apart' — from 'se-' (apart) + 'claudere' (to shut). Isolation by closure.
To keep apart from others; to isolate or withdraw into privacy; to screen from view.
From Latin sēclūdere (to shut off, to isolate, to separate by closing), composed of sē- (apart, away from, without — a prefix expressing separation or removal) and claudere (to shut, to close, to bar), from PIE *klāu- (hook, peg, nail — the physical implement used to bar a door). The PIE root *klāu- gave Latin clāvis (key, the instrument that closes), clāvus (nail), and claudere, producing English close, clause, include, exclude, conclude, and preclude. The prefix sē- (apart, without) appears also in separate (se + parāre), secure (se + cūra, free
A 'secluded beach' is literally a beach that has been 'closed apart' from the world. The word 'recluse' comes from the same root with a different prefix — a recluse is someone who has 'closed themselves back' from society. Both words turn the physical act of shutting a door into a metaphor for withdrawal from human contact.