Yeah, it looks like in a couple areas you accidently got your terrain off the isometrical pattern and that's where you had problems, I've done that a lot, it's not too difficult to fix though, you just have to go over it again and move some of the tiles around a bit.
On the first one, have you tried looking for a less repetitive blend for the temple? Like the one
here made by JaBoK a little while back? It may not fit with how you need it though, if it's at all possible, try to find a slightly less repetitive blend, also, you extended the bottom of the temple a bit too far, making it look much worse, since it doesn't turn properly on that corner like it's supposed to, try evening that corner a bit. Also, I understand that you are trying to do an extended staircase, but since it's already going to a normal sized wall, why not just use the normal stairs? Stairs tend to look bad, no matter how hard you try unless you are mirroring them or using the normal staircase.
Now, for the second one, it looks like you knew how to do stacked cliffs, and you just got lazy on the right size, that's a quick fix, and if you need a precise method on how to do stacked cliffs,
here's a tutorial I made that shows the most direct way to do them. Also, the water edge on the right side is a quick fix, you just inverted the top of it, just flip it the other direction and it should match with the underwater parts perfectly. On the bottom left, I love the attempt at the water to bridge to ruins to dirt look, the only thing I can say for that is try to find tiles that fit together a little better, and also you can make the bridge blend into the ruins a little better by using the darker parts of the bridge, if you don't get what I mean, check out steps 6-8 of
this tutorial, the bottoms of bridges have a slightly darker edge, and that blends with ruins much better than the lighter parts on the rest of the bridge.
Overall, great for a first try, as much critiquing as I did, it's a very good try, I like it, most of the errors just look to me like you got lazy. Good luck fixing it
None.