Sure, here are 10 useful features that can help distinguish an airfield in a photo:

1. Runways: The most prominent feature of an airfield is its runway. Runways are typically long, straight, and made of asphalt or concrete. They may have markings and lights that help pilots navigate.

2. Taxiways: These are the roads that aircraft use to move around the airfield. They are usually narrower than runways and may have different markings.

3. Aprons: These are the areas where aircraft park, load and unload passengers and cargo, and refuel. They are usually located near the terminal building.

4. Terminal buildings: These are the buildings where passengers check-in, pass through security, and wait for their flights. They may have distinctive architecture and signage.

5. Control tower: This is the tall structure from which air traffic controllers direct aircraft movements on the ground and in the air. It is usually located near the center of the airfield.

6. Hangars: These are the large buildings where aircraft are stored and maintained. They may have distinctive shapes and sizes.

7. Aircraft: The types of aircraft present on the airfield can provide clues to its size and function. Commercial airliners, military jets, and private planes all have different characteristics.

8. Fences and security measures: Airfields are typically surrounded by high fences or walls to keep unauthorized people out. They may also have security cameras and other measures in place.

9. Markings and signs: Runways, taxiways, and other parts of the airfield may have different markings and signs that help pilots navigate.

10. Surrounding terrain: The terrain surrounding the airfield can also provide clues to its location and function. Airfields located in urban areas may have more buildings and infrastructure nearby, while those in rural areas may be surrounded by fields or forests.