This is something I discovered while messing around with a fluid simulation. If you mess around with the values and get it just right with an inflow setting you can go to a certain frame and hit alt-c curve from mesh and then alt-c mesh from curve/meta/surf/text you will get a frozen fluid as a solid mesh, which, if done properly, can look something like a neat cave. This is what I got after adding some materials and lighting.:eyebrowlift2::spin:
Great work