```

Copy this code and paste it in the editor, then hit `Run` and `Save and Close`. As you might have guessed, this puts a block on the coordinates `(0, 0, 0)`. The fourth value is the unique identifier for the Grass block to be placed. There is a list of unique ids for each built-in block, but what if we want to place a custom block instead?

[Create a custom block](/wiki/build/how-do-i-make-my-own-custom-blocks), for instance `My Block`. Then replace your previous code with this one:

```js

// Find the block called "My Block"