Three nuclear bunkers used during the Cold War will go under the hammer to be sold off to the highest bidder.
This bunker in Llangollen is for sale
The shelters in Llangollen, Machynlleth and Rhewl near Ruthin are for sale on internet auction site eBay.
Former Royal Observer Corp bunkers sold previously across the UK have sold for thousands of pounds.
The bunkers in north and mid Wales are owned by Crown Castle UK Ltd, a telecommunications company, which acquired them when they took over a firm called Millennium.
They were bought when the UK government sold them off.
Crown Castle has been looking to use them as sites for the erection of communications masts.
However, those being sold off were not adequate said Nicky Banks of estate agents Grounds and Co, which is arranging the sale.
"The signal wasn't good enough in the area, or they couldn't get planning permission or there were too many [masts] in the area already," she said.
"The bunkers are ideal because they have a small enough piece of land and they have the infrastructure to tie a mast on."
Above ground, the Llangollen site is 15m by 16m, Rhewl is 14m by 12m and Machynlleth is 16m by 14m.
The actual rooms are accessed by means of a single fixed ladder and lie about 15ft below ground.
"Anyone bigger than 18 stone would struggle to get down," said Ms Banks.
She said they company have no idea how the bunkers will sell.
"We've had lots of interest in some and none at all in others," she said.
"Of the three in Wales, the site at Llangollen is expected to be the most popular, offering views of the ruins of Valle Crucis Abbey and of Llangollen itself.
"People want them for wine storage or to store documents. They have got weird and wonderful uses," she added.
The eBay auction opens on Thursday and runs for ten days.
Grounds and Co expects each of the three sites to go for at least £2,000.