It's always fun to revisit old favorites and see what else you can unearth.
I noticed a friend in the CoT and decided to go out and mess around a bit. Upon doing so, I found soothing somewhat interesting, and defiantly worth heading out there once more even if you've been many times before.
Start by going to the main room and to the tower on the West side of the great hourglass.
Walk up the stairs to the top of the tower. Once you're at the top you will notice directly in front of you where the tower meets the rock wall, you can wedge your self in and jump/tap forward your self to the top of the rock wall.
Once you're at the top of the "wedge" to your left you will see a thin line of where the rock wall comes to a peak. Walk along this peak carefully making sure not to fall to the left or right. You might want to turn your brightness up all the way. As you can see it gets pretty dark up here and can be confusing as to where you're going. Be careful not to wander too far out. If you walk past the textured area you will fall off the map and die.
Now you're at the top outer rock wall. You can now explore everything from above. You can either chose to follow the "outer ring" left or right.
If you go to the left and follow along what almost appears to be a walkway with a series of bridges, you will be above the "great hourglass" at which point you can slow fall onto the hourglass. I unfortunately did not have any slow fall on me at the time so I did not get to test this out. From what I’ve seen in videos I’m assuming that if you jump from here and land up high enough on the hourglass that you can walk up towards the neck area and fall through.
If you turn right instead, you will find yourself above the instances (which have an invisible wall behind them). If you walk to the very edge above one of the instances (the first you come to) and jump off (careful if you're not a rogue you may need slowfall or teleport/iceblock) you will find that you can actually land behind the instances invisible wall.
Enjoy
P.S. For those that need to be spoon fed and don't know how to get into the CoT, or how to even find out how to; tough luck. L2search