# Select area
Whiffle Wind automatically suggests an LES domain based on your turbine and met mast positions, as described in Step 2 of [Under the Hood](https://docs.whiffle.cloud/getting-started/pages/gI7OQT4p6CdYKEWRO83J#id-2.-calculating-the-les-domain). However, there may be cases where a simulation does not include turbines or met masts, or where the LES domain requires manual extension, for example to encompass additional terrain features such as nearby mountains or landmasses.
For this purpose, we provide the **Select Area** functionality. To use it, navigate to the Site step and open the **Select Area** panel. Click **Draw Area** to enter drawing mode, where you can define a rectangular area of interest directly on the map. The suggested LES domain will then be extended automatically to incorporate the additional area.
The LES domain can only be enlarged by drawing an area, not reduced. This ensures the LES is always of sufficient size to produce reliable results for your wind farm and turbine locations.
{% hint style="warning" %}
Manual extension of the LES domain is at the user's own discretion. Please be advised to revise our best practices below and contact Whiffle Support when in doubt.
{% endhint %}
### Best practices
#### Including a neigbouring landmass
To include an additional landmass or geographical feature close to your landmass, we recommend to draw the additional area only around the geographical feature. This will provide the optimal LES domain based on the additional area and turbines.
#### Horizontal extrapolation
To enlarge the LES domain in all directions, for example when defining an area for horizontal extrapolation, draw the additional area around the pre-calculated LES domain. The domain will then automatically extend to include the added area of interest.
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://docs.whiffle.cloud/getting-started/select-area.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.