Hey there JustWyren, this is just my personal opinion on your parkour map, you don't need to take in my feedback if you don't want to and I'm only here to help you, I am a moderator but I'm not grading your build just having a little review of it.
Your map name is quite descriptive and definitely explains what your map is which is always what I like to see, I hate doing maps that have a name that is completely different from the actual theme of the build, great job with that section. Your map is certainly beautiful from the inside/interior and it seems you put quite a lot of work into that section, what I would recommend is that you spice up your interior as it's just a wall of stone/dirt and looks quite ugly, maybe add a wall or some ancient relic carvings there, idk just my idea :)
Block variety ~ Your parkour map certainly has some nice block variety and looks quite unique from my perspective, I love that you added slime block and fence jumps as it just makes the map more of a blessing to play and mess around with. I'm just gonna add this in here but the theme from my perspective seems flawless, I don't really think there are any other map submissions with builds that are similar to this, great job on your submission!
Best of luck :D