The lay of the land
Definition 1 of 2
Pro Tip 1/3Outdoor Planning
Used when preparing for outdoor activities, knowing the area's geography can be crucial for safety and success. 
Before the hiking trip, they discussed the lay of the land to avoid getting lost.
Pro Tip 2/3Visual Description
The phrase often implies giving a detailed description that helps someone visualize the area. 
The guide explained the lay of the land so we could picture the mountain trails clearly.
Pro Tip 3/3Before Construction
It's used to emphasize the importance of understanding an area's geography before starting to build or develop. 
The architect surveyed the lay of the land to design a house that fit the environment.