Sun Wukong stared up at the light blue sky, watching the clouds pass by overhead. It was all he could do at the moment. It was useless to try to escape. He would squirm, yell, try to get his fists free, but it was all just wasted energy, and he knew that they'd be fruitless attempts at escape, for Sun Wukong was currently trapped beneath the 5 Phases mountain. He had been trapped for roughly 500 years now. Any person who knew the stories of the Great Sage Equal of Heaven would have asked "Why can't he just blow it up?" Or "Can't he transform to get out it?" Or any of those types of questions all to which the answer is a firm no.
See, after pissing off half of the Celestial Realm, Buddha trapped Wukong beneath the mountain. Knowing that Wukong wouldn't even break a sweat getting out from under it, a magic talisman was placed atop the mountain, sealing Wukong beneath it and stripping him of his powers.
Wukong got used to zoning out now, the only entertainment coming from the stray bird every now and then. But, little did he know, he was just about to encounter his key to getting out of this mess.