How to make tunnel in Little Alchemy

To make tunnel in Little Alchemy you have to combine this elements:

1. engineer + mountain

Tunnel Step by Step

How do I combine the necessary elements to create tunnel in Little Alchemy?
Here we show you the walkthrough, just follow the steps below:

1 air + fire = energy

2 earth + water = mud

3 earth + fire = lava

4 air + water = rain

5 earth + energy = earthquake

6 air + lava = stone

7 earth + rain = plant

8 earth + earthquake = mountain

9 fire + stone = metal

10 mud + plant = swamp

11 energy + swamp = life

12 earth + life = human

13 human + metal = tool

14 human + tool = engineer

15 engineer + mountain = tunnel

Below you can see a video tutorial on how to make tunnel in Little Alchemy:

Combinations with other elements are not yet known.