Cliff Cave is fun but pretty short, SIUE is a little bit of a drive but defenatly worth checking out has great flowy singletrack. I havent been yet but planning a weekend trip down to council bluffs in Potosi, i heard its a great ride plus you have acess to an extensive trail system that leads out of the park. By far one of my favorites is Klondike park in Defiance MO. Has technical obsticals like teater tottors and a bunch of wood bridges. There are 2 trails here and the one going down from the cliff is pretty awesome too, very fast and usually wet. hope this helps