Nick on the Rocks - Ape Cave 

44zz xmr 77

If you're kidding, go f yourself. If you're not, look it up! There's plenty of good research on it. You can see them being formed in Hawaii as we speak

The secret is that the outside of a flow is exposed to the air whereas the middle of the flow isn’t, allowing it to remain hot enough to continue to flow, and empty the tube-like crust surrounded it, leaving the empty tube behind. There, now you know.

Yes... you need a break. Start with the internet.

The other secret is the incline of the tube and the resistance to the flow, making the pressure in the tube even.

The Ape Caves/Lava Tubes is the result of a Lava Flow Type called: "Malfic" and these type of flows are relatively thin flows they can move great distances, The speed of lava varies based primarily on its viscosity, the slope angle it follows, and its core temperature. In general, lava flows move slowly. Example: The typical speed for Hawaiian basaltic flow is 0.40 km/h (0.25 mph) and maximum speeds of 10 to 48 km/h (6 to 30 mph) on steep slopes Pāhoehoe (also spelled pahoehoe, from Hawaiian meaning "smooth, unbroken lava") is basaltic lava that has a smooth, billowy, undulating, or ropy surface. These surface features are due to the movement of very fluid lava under a congealing surface crust. A pāhoehoe flow typically advances as a series of small lobes and toes that continually break out from a cooled crust. It also forms lava tubes where the minimal heat loss maintains a low viscosity.