Former Ysgol Hen Colwyn headmaster, Gareth Davies, and wife Elfa, arrived at their home on Wynnstay Road, Old Colwyn following a family holiday in Nottingham to discover their three foot antique-styled sundial and wooden bench had disappeared.
Thieves made off with the items from the couple's front garden, but abandoned the heavy loot just 150 yards away.
Mr Davies, said: "We returned home from holiday to find the sundial and the bench had gone missing.
"While we were away neighbours called the police. When the police arrived to collect the items, health and safety regulations prevented them from putting the items in the boot because they were too heavy, so they called the council.
"The council came at some stage but when they did there was nothing there."
The couple believe the original theft was a prank by a group of teenagers who never intended to keep the ornaments.
Mr Davies said: "The probable thing we think happened is that someone saw them on the road and thought they were too good to be thrown out and took them.
The bench and sundial were on the road for well over 24 hours, it was an open invitation for someone to take them.
"The bench is a rustic log bench, it is very heavy and really matched the house. It is an unusual sundial in unique antique style with a bird bath and a weather vein. There was a man-made crack on the side to make it look genuine. We have been looking around and we haven't been able to find anything like this one."
A police spokesperson said officers were conducting door to door enquires and reviewing CCTV footage.
Mr and Mrs Davies are appealing for anyone who may have picked up the items thinking they had been discarded to contact them on 01492 516694.
If you have any information on the location of the items you can contact North Wales Police on 0845 6071002 (English line) or 0845 6071001 (Welsh line).