If you want to keep your sculpture out of doors and are worried about its being stolen or knocked over, there are various measures you can take.
The simplest to put into effect (and it is quite effective) is to drill into the base from underneath with a masonry bit - ideally a thick bit (approx. 12 mm) - choose a place which has as much depth as possible. You can ask us to do this for you before delivery but, if it is too late for that, it isn’t difficult to do.
After drilling, the drill bit itself makes an ideal ‘peg’. It is strong, exactly the right size and the thread enables adhesive to ‘grip’ it well. You then need something underneath the sculpture to secure the peg into. This could be, for instance, a bed of concrete, a stone slab or just a simple concrete paving slab (or two) from a D.I.Y. store (this base can be buried if you’d prefer it to be invisible). It will need a hole drilled in it to correspond with the hole in the sculpture. The two holes need, of course, to be long enough between them to swallow up the peg which can then be glued (with an epoxy resin like super-glue or araldite) into the sculpture and glued (or cemented) into the base.
The advantage and disadvantage of this method is that the sculpture cannot be moved by anyone (including you) unless the base goes with it.
Other methods include screwing ‘z’-shaped brackets into a base to ‘hook’ over the edge of the sculpture’s base. This is less permanent but, unless you can hide the screw-heads, they can be unscrewed by someone other than you.