Endless Tunnel Tutorial - Vanilla Minecraft

A basic little tutorial for creating (seemingly) endless tunnels in minecraft by using just 2 command blocks.
Command:
execute as @a[distance=..2] at @s run tp @s ~ ~ ~-4
execute as @a[distance=..2] at @s run tp @s ~ ~ ~4

*the ~ ~ ~4 and ~ ~ ~-4 can be replaced depending on the coordinates of your own builds i.e. ~12 ~ ~