Head to the Huge Cave seed and be amazed that an underground space can be of such staggering proportions. The great news is that you can find caves here with a new block - Dripstone, appendages inside the caves. And also be careful, because here you will meet various creatures that will not be very happy that you found them.
Below are screenshots and coordinates of some locations.
To search for the Drip Stone Cave, enter -200 -14 390:
To go to the ground use the coordinates -75 45 350:
If you want to get into the underground pool, use the following data -149 17 318:
Also a godsend for you will be caves where you can collect diamonds, a lot of diamonds:
