Just a huge amount of high class high quality hard problems. There are plenty of problems above 7A level, but not many underneath. Most of the problems are high with good landings. The concentration of hard high boulders in a very small area might be the highest in Fontainebleau. Rock quality is mostly top notch, but some of the lower boulders seem to leak water forever. Please respect that, and don't climb boulders with wet holds. The rock quality is soft around Éléphant.
Some mega classics around:
Tour de Garde 7A
Sans Papier 7C
just to mention a few. The area is mostly shady and cool when the other side of the hill is sunny and hot. Also very quiet area compared to the main area. There are some boulders without names and knowledge what they are. The area used to feature an red circuit but it's forgotten. Still many of the old reds are possible still to climb.