If the land behind a house is sloped down (a small hill) can you put a pool?

Define small and expensive.

I currently live in the basement and my sister was looking into cutting a hole in the basement wall and putting in stairs that go outside. Oh my permits.. This was mainly for a fire escape. We have just decided to cut a hole in the floor and build a hatch so I can escape since it will be a million times cheaper.

It depends on a lot of stuff.

What is the soil? Clay? Sandy? Rocky?

There are just too many unknowns – you would need an expert to tell you for sure.

@elbanditoroso Actually, it tends to be rocky there, so digging might be very expensive. Maybe the cost of the wall is counterbalanced by not having to dig out rock.

When I was young, a friend lived on a steep hill and her husband was a carpenter. The hubby built a series of terraces out of wood, wood deck terraces, and they had somewhat of a back yard with those.

My mom had a good friend who had a similar piece of property. The backyard was a steep hill. She hired someone to build a terraced deck and at the bottom was a pool. It was probably an above ground pool but was surrounded by the deck, so it was not elevated, you would jump into it. It was really nice. The levels were big enough so she had little tables on them and could sit and have lunch or whatever.

You could save on the cement wall by simply having a sloping pool.

My neighbors have a pool on a (fairly steep) hill. It’s certainly possible, but I have no idea how much it cost.

My sister just did this with her house that is atop a rise with a slight down slope away from the home. Instead of a retaining wall type approach they simply regraded the property and essentially buried the pool instead of having to excavate.

Yes. They will have to build decking straight out for the pool and then the sides of the pool will have to be covered with a wooden structure or block walls.
https://www.poolproducts.com/blog/how-to-build-a-pool-what-to-do-with-a-sloped-backyard

Terracing

Thanks everyone!

Dammed if I know.

Pools get expensive fast. I looked into a small one and it was going to be like 40k before we even addressed a tree removal and relocating our sewer line. That was going to add on another 20–30k so not happening, it’s just easier to find a house that already has one. I know pools can be built into a hillside like that but I would be prepared for sticker shock.