**High beam headlights**, also known as **road lights**, are powerful lights that illuminate a great distance in front of the vehicle. These lights are white and can dazzle other drivers if not used properly.

- **It is prohibited to use high beam headlights within towns and cities**. This is because these areas are usually well-lit, and the use of such powerful lights could dazzle other drivers and pedestrians, creating dangerous situations.

- High beam headlights are designed to be used on **roads outside urban areas**, especially when there is little natural light, such as during the night or in poorly lit tunnels outside a municipality. In these situations, they help improve the driver's visibility without the risk of dazzling others, as traffic is less dense.

Therefore, the correct answer is that it is prohibited to drive with high beam headlights **within built-up areas**.