num_pages: 121
description: When they move their meeting place to a hidden cave, the Secret Seven stumble across evidence of a mailbag robbery.
language: English
title: The Secret Seven and The Hidden Cave Adventure
titlecomplete: The Secret Seven and The Hidden Cave Adventure (Secret Seven Adventures Series)
genres: 20th Century, Young Adult, Classics, Childrens, Adventure, Novels, Fiction, Detective, Mystery, British Literature
ratings_count: 3608
series: The Secret Seven
publisher: Childrens Press, Chicago