I recently started a patio project in my back yard. I got a great deal on 3500 holland pavers that were left over from a large project. My patio only needs about 2/3 of the pavers. Im trying to decide how best to use the rest.

I would like to make a retaining wall and a fireplace with them. Can I mortar these pavers as if they were bricks to make a fireplace? Are there any reasons not to use them?

All the pavers are the same size: 8" W x 1.75" H x 4" D

http://www.lowes.com/lowes/lkn?action=productDetail&productId=123114-299-123114