Since the original Mario and Luigi have retired so this warp zone is looking a little out of shape. I tried warping to world 8 after placing this cache but my legs got stuck and when I became free I just went home.
You can either park on the gravel parking spot/old trail. Or drive up to this cache. It is quite rocky out there since Koopa's grand children used to play here.
Inside you will find the usual swag... or maybe a little more then the usual.