I created a stone wall based on the tutorial >>>>>>>>>>>>>
http://www.lunacore.com/photoshop/tutorials/tut028.htm
I do believe I altered the colors to suit myself, but I'm not positive. The doorway was later removed due to perspective and fit issues. A separate door was created later.
step 3 of 5
I made several different wall sections, applying perspective to the wall that goes beside the stairs, then a different wall for the entryway to the right. Note the harsh edges and contrived shape of the stones and outer corners.
step 4 of 5
For the background I tried numerous options, then decided on my painting shown as the way to go. Don't worry, I cloned my name out of it.
step 5 of 5
For this step I turned off the stair layer to show where the shading had begun. A lot of additional time went into giving the grout of the stones, the face of the stones, and the edges of the stones more believable form and texture.