I work in the US and every year I take 17 days off over the July period which works out (with another company holiday) to be 4 continuous weeks. The first year I did it I told my manager "I'm going to take three weeks off, but what do you think about four?". I got my three weeks and made myself indispensable enough to get the four the next year.

This stuff can be negotiable if asked for and planned correctly. It won't be offered.

The Danes do it best, they basically shut down the country for 3 months every summer and have an unspoken agreement that nothing will get done.