Actually, there are a number of kits like this, usually available from a local masonry supplier, stone yard or landscaping outfit. There aren't any instructions that I remember, but they are super easy to assemble.

The hardest thing to "D-I-Y" is to get the base level, set and tamped before installing the pavers so you have a stable base.

The blocks are trapezoids in various sizes to be able to create curved walls. Some are more angled for smaller radii, some are less angled for larger radii. You will also need a good masonry saw (buy or rent) to cut a few of the blocks. Alternating different sized blocks will allow you to work to a radius you mark out on your patio surface.

The cap block in the photo is a little thinner, deeper and a different color to create a more finished look.

Here is a link to a firepit to get you started:

http://www.outdoorlivingkits.com/grand-fire-ring-kit.htm

You can do a dealer search on the site to find someone local.

Check with your local authorities for restrictions, but generally a wood firepit requires a sparkscreen to contain sparks and floating embers. It will also have to be at least ten feet away from the house, and some jurisdictions may require it to be ten feet from anything combustible, including decks.

Many manufacturers offer a D-I-Y video. I firmly agree about making sure you get the base done right. Enjoy, firepits add a lot of outdoor enjoyment.

Excellent!

What are dimensions of the bench?

We didn't build the bench, so I can only guess. I imagine the inside diameter of the bench is about 10' -11', and the bench itself is about 3' deep. The seat will be about 16" - 18" high, and the back is probably about 30" high.

Is the back safe? It looks like I wouldn't want people to relax completely kinda.... I might be wrong...

Excellent work CATHY

Allybina - I'm not sure I understand your question about the back being "safe". If you are asking if the seat walls are sturdy, I can assure you they are very solid.