Question about pipes in bathroom (photos)

Hello, we're remodeling our guest bathroom and we were going to make some shelves that go INTO the walls but when we removed the old vanity and some of the wall, there were some huge pipes that were in the way. My wife wants to have the pipes removed and rerouted so that she can have her in-the-wall shelves, but I don't feel too comfortable doing that. The pipes look pretty big and I'm not sure it's worth it. Can someone tell me what kind of pipes these are? Are these the main pipes that feed into the rest of our home?

Thanks in advance!

Here is a photo of our bathroom prior to opening the wall.



Here are photos of what the pipes in the walls look like.





Any help would be greatly appreciated.

These are your vents.
Without those, your plumbing doesn't drain right, and the traps siphon dry.
They can be rerouted higher, but that would just be in your way.
They can't be placed lower, they need to be 6" above your counter height.

shelves in the wall, facing the sink? Can you work around the one big horizontal pipe? The wood you see may be able to disappear to make room for the biggest shelves possible.

david