Fontainebleau offers two great attractions that complement each other well: the Palace, one of the most historically rich royal residences in France, and the Forest, a vast woodland famous worldwide for bouldering. Most day-trippers focus on one or the other; if you have a full day, you can do both.
The bouldering in the forest around Fontainebleau is genuinely world-class. The sandstone boulders are arranged in colour-coded circuits graded by difficulty, and the tradition dates back to the 1870s — these are the circuits that inspired every climbing grading system in use today. Schools in town offer instruction for beginners; experienced climbers will already know what they’re coming for.