It's just foot golf. Orlando has some of the best Disc Golf courses in Florida and since Disc Golf exploded the last two years I'm surprised Disney hasn't cashed in on having a "Disney themed" course nearby.
Mission: SPACE is probably my second or third favorite ride so that would be my choice outside of the fact that Trees > Ratatouille was just a park expansion which is the correct answer.
Based on this bioreconstruct picture where is the future entrance going to be. They cut off the old entrance with new plants but that seems to be the only possible access from this side.