I want to build a large, horizontal underground tunnel that spans my world, for quick travel. Unfortunately, if I tunnel under a desert all the sand falls down and I just make a giant hole wherever my tunnel is. I could put a layer of stone above the tunnel to support the sand, but I can't find a way to make space to put the stone without the sand falling.

One solution I have thought of is to dig out the entire desert, build my tunnel, and then put all the sand back, but that doesn't sound like fun at all.

EDIT: The solution I decided to go with is just dig below the desert. I am making my "subway" at a depth of "level" (0), so hopefully I won't have much trouble with sand. Thanks for the suggestions!

  • I embarked on the same project recently and just went with stopping the tunnel near the desert and using a skybridge over the desert. Seems like it would be more elegant to just use a skybridge from the outset, or a tunnel deep enough it never hits the desert. Jul 26 '11 at 13:10
  • 3
    @Jonathan Skybridge can cost your meteor bricks, so deeper is preferred.
    – tzenes
    Jul 26 '11 at 23:36
  • you could also build a road over the desert by laying dirt/stone on top of the sand/ wont cost you meteorite but will presumably prevent cacti growing
    – jk.
    Jul 31 '11 at 10:40
  • 1
    Man, half the time I read a terraria question title, and I think it's a Minecraft question... :)
    – Cyclops
    Jul 31 '11 at 12:33
  • They are really similar. Though now that I think about it, this would be a problem in Minecraft too. Aug 1 '11 at 16:50

I don't think what you're trying to do is possible, but the easiest solution in this case is to just dig your tunnel under the desert a little bit deeper. Eventually the sand gives way to stone if you keep going down, and it shouldn't even take that long to get there. Make a stairway down until you have an ample buffer of stone above you and then dig your tunnel across.

  • Do you know the depth at which the sand gives way to stone? I actually haven't hit the desert with my tunnel yet, so I'm not even sure if this will be a problem. Jul 26 '11 at 15:56
  • @Mike Cooper - it's not very deep, but the amount is dependent on world size I believe.
    – peacedog
    May 22 '13 at 11:46

It is possible in multiplayer for one person to dig the sand while another inserts a block while the sand is falling.

The sand creates a void long enough while falling for another player to quickly add a block of dirt and stop the sand from falling.


I've developed a technique that's slow but better than mining the whole thing out.

  1. place a bomb at the base of the sand you are digging through
  2. jump and grapple about 4-5 blocks above it
  3. be ready to place a stone block in immediately at the time of detonation

It's slow work, you go through a lot of bombs, and it's very easy to blow yourself up. But hey, anything to preserve the ton of sand above it.


So I didn't find a full solution to this problem but I did find the following:

If you build a chest on top of sand, that top layer of sand will not fall.

While this doesn't prevent you from having to dig out most of the sand, it does allow you to preserve a top layer.

You can try digging deep enough so there is no sand, but I believe the guaranteed level is:

Small   ~700 ft
Medium   ~850 ft
Large    ~1000 ft
  • This is by far the best solution for dealing with sand from the ocean.
    – Daerik
    Sep 8 '17 at 16:21

From How to dig under sand (solo) in 11 easy steps

  1. Place a double row of actuators in the sand, just about head height
  2. Install the switch
  3. Wire them together
  4. Flip the switch
  5. Make a dam on the open side
  6. Pour in one bucket of water (order matters)
  7. Pour in one bucket of lava
  8. Flip the switch again
  9. Dig out the row of sand containing the liquids
  10. Dig under the Obsidian
  11. Remove dam and mechanisms
  • My intent was to remove exactly what I removed, because it's misuse of tags and causes issues. Please do not revert this edit.
    – Wrigglenite
    Sep 5 '17 at 21:33

Unfortunately, that's the only solution and what would ironically take longer than if you simply removed all the sand to begin with.

However, an alternative could be to tunnel upwards and level the sand at the surface by adding sand where there isn't and removing sand where there is, which would allow you to continue much faster, and still keeping a flat surface to run across so you can travel more effectively.

  • cacti, vultures and antlions would hamper you on the surface though
    – jk.
    Jul 27 '11 at 6:49
  • @jk.: Cacti is actually much faster to remove by digging the sand under it rather than chopping them down. Unlike trees, cacti don't prevent digging in the soil under them. Oct 27 '16 at 9:18

The only way to do this (in single player) would be cut and cover, i.e. (for bottom up)

  1. dig all the sand out to the level of the tunnel floor
  2. create a tunnel roof out of stone or dirt
  3. backfill the space above the tunnel roof with your vast reserves of sand

Which would take a lot longer than simply going around the desert one way or other. however it is possible if you really want a same level tunnel across the world.

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