Emergency Fund options

Wondering what best options are to store emergency funds besides the obvious savings account or under the mattress? Or at the bottom of a cereal box, as i recently came to know via a burglary. Our cereal boxes were raided and the police told us that old folks often keep money there. Who would have known? What are best options outside the home? thanks

In french there is the expression “avoir du blé” which means to have money but that translate literally as to have cereal.

I thought about buying a safe to keep documents, bank tokens, and money there. But it’s so inconvenient if you’re renting a flat. A safe should be really well mounted. Currently when the putzfrau comes, I’m always home, because I just don’t trust a stranger to have my key and be alone in my flat. But if all the important stuff was locked in, then maybe I would be more relaxed…