One of the nice Cities of Death models released were the resin Ork Barricades. Six resin barricades (still available) that have a very Orkiness about them.
Orks are adapt at banging together large piles of debris, welding them with burnas and Gretchin for extra stickiness. In dense city-fights, cunning Ork Warbosses use these barricades to funnel enemy troops and prevent their armour from manoeuvring, before their Tankbustas launch a devastating ambush.
These are going to be part of what hopefully will be an Ork city.
Here is one of the barricades.
This is probably my favourite and makes use of an old Ork Trukk.