You can find the German original, Der Zauberberg , on Project Gutenberg . Spanish translations are widely available on platforms like Penguin Random House [].
A high-quality epub of this novel should include active table of contents (TOC) for navigation, embedded metadata , and properly formatted footnotes , as it is a deeply intellectual text.
La Montaña Mágica (The Magic Mountain) by Thomas Mann is a cornerstone of 20th-century literature, often available in digital (epub) formats from reputable sources.
The novel focuses on the "cyclical nature of time" and the "unexplained (and unstoppable) illness" of its characters in a tuberculosis sanatorium. La montaña mágica by Thomas Mann | Goodreads