After digging a pit in a useless sloping part of the garden I chose to make a retaining wall of wooden logs. I have no picture of the actual digging as no one had any idea what was being done then.

Power tools - you have to love them! And some ten inch nails, some reinforcing steel bars were cut up and used as pegs as I ran out of proper nails.

Here is a ton (1000kg) of natural flat stones from a kind person's garden. They give these away for free!? Big, irregular and very heavy, just to make sure it would be difficult and backbreaking.

I prepared the surface for the stone floor. I tried levelling-out as well as possible by removing most stones from the top layer.

Pick axe or similar (this is more like a shovel axe) was useful when loosening up the soil and any embedded stones.

More stones than expected. Surface good enough to start laying the stone floor surface.

I realised it was best to start laying stones along the perimeter. Biggest stones first reducing as I went inwards. The very first stones must be placed in corners. It's just like any jigsaw puzzle.

Here you see the pattern growing inwards from the log perimeter towards the centre.

And when stones did not fit I simply had to do something about it, as here with a chisel and a sledge hammer (I must get some sort of power tool if I ever do this again).

The stones fit quite well after some puzzling.

Just one little rest in my bamboo hammock...

I brushed a little sand and gravel into the gaps to fixate the stones. Coming up; the fireplace itself. To be made of ordinary rubble stone at the centre of this stone floor.

I would have preferred more cubical shapes for stability for the actual fireplace, but this is what I found in the neighbourhood. It just feels right using building material that others think is junk.

Cement. I chose a type that is already mixed with some sand, almost like a bread mix. Just add water and you have concrete!

Make sure to wear some protection (for handling cement that is). I suggest reinforced blue rubber gloves.

This is how concrete looks when you manually mix it with a shovel in a wheelbarrow. One bag of 25 kg cement with 0-4 mm sand to which I added 3 litres of water.

Don't try to use my wheelbarrow method for cylindrical structures like this 4 m high mystery that I stumbled upon in the woods.

And by no means try using it for 100 m high curved arch dams like this...

My aim was a more modest height of 50 cm, making it scale model of 1:200 to the dam. So for the foundation I placed a first layer of concrete to fix the first stones at the centre of the pit.

The first batch of concrete was enough for the basic shape. Rain started, so this was a good time to let the first layer cure under a tarpaulin to protect it from washing out the mortar.

Next day, sun was back, so on to the next batch.

More stones added. A bit rough, but that's all to plan. You could build it with ordinary bricks all at right angles and so on, but what's the fun in that?

More or less complete. I forgot to show it, but I left a few small vent holes near the bottom to allow some ventilation for the fireplace and to let rain water drain out.

There it is, ready.

Blazing fire test.