Drainage help!

[mo-uk]

My old patio consisted of pavers and just normal concrete. which i am currently tkaing up

The concrete paving was basically where all the slugdy mud and bit of wood is:
http://img190.imageshack.us/i/img0642m.jpg/

you can note the drain to the right which has paintbrushes in water (and it covered up at the moment).

to the left of the picture we have an outdoor toilet - which i guess links to the drain

problem is, as i was cleaning away the mud, i noticed a small hole in the ground (and the smell) and it seems that i can kind of see through into the drainage.

http://img190.imageshack.us/i/img0651m.jpg/

the bigger issue seems to be that there is very little between the drain now and the floor - i.e i could probably easily bash my way into the drain!

the other issue is that i need to big deeper to get the right level for my patio AND the concrete next to it needs to be bashed away

i have someone coming but does anyone know what the crack is here? surely the drainage is carried insomesort of metal pipe? could i just bash in the floor and fill it in (once checked by a pro of course).

I am a bit worried about how thin the layer of floor that is left is.

i haven't tried messing about with any other part to the left of the hole but i imagien its equally as thin

any thoughts?

the gallery of pics is here:
http://img190.imageshack.us/gal.php?g=img0642m.jpg

[Tony McC]

Drainage pipes are *rarely* metal. The most common materials are plastic and, as you have, earthenware (clay).

What happened with the "someone that was coming"?