Pretty cool! We made a pretty big cave with PVC pipes and lava rock attached with silicone. You can take the dust leftover in the bag and sprinkle it on top of the wet glue/silicone to cover it. Works really well.
Was a lot of fun and pretty simple with a pretty natural look.
Juk1993 
this looks awesome. what features should i aim for to make a good rockery?
Pretty cool! We made a pretty big cave with PVC pipes and lava rock attached with silicone. You can take the dust leftover in the bag and sprinkle it on top of the wet glue/silicone to cover it. Works really well.
Was a lot of fun and pretty simple with a pretty natural look.