Sounds like a stone or brick or concrete block cellar parged on the inside with "plaster".

You can make simple white plaster or stucco with sifted sand, white portland cement, and lime with a ratio about 4-2-1. It doesn't have to be exact. You just shovel it into a wheelbarrow and mix it with a hoe. If it doesn't want to stick add more lime to the next batch.

You can make the walls for a root cellar very easily with concret blocks stacked up dry, and parge the sides with fiberglass reinforced mortar. You can buy this at building suppliers, it come pre-mixed in bags under various brand names. It makes the block walls immensley strong. Of course you need footings under the walls, could be just a trench with gravel in it.
The roof is trickier if it is going to be masonry. If it isn't accessable by a concrete truck to pour a flat cieling, you could cobble up an arched wood form and lay brick and mortar over it, maybe two layers with the joints staggered and brick ties in the joints. Parge over the top with stucco.

I have had success just storing potatoes in a hole in the ground covered with sawdust or leaves and a piece of plywood over. A lot easier!

there is a really good root cellar book i have but i don't remember the name of it! ahhh! i will try to remember to look when i am near it. it is a good book on root cellars.

Thank you wild garden -- you sure have answered our question!!!

wild garden, is the book you're thinking of Root Cellaring by John (?) and Nancy Bubel?

that's it kayva :)

OK, folks. Husband has decided to go the buried freezer way for a root cellar this year. He has 2 old freezers outside and plans to bury them with lid intact, put plywood over top, rain-tight tarp and bales of hay on top. Worried about air circulation, any hole in the freezer would invite mice and worse. What to do from here? HELP...

Here's a good site that explains the in's out out's of root cellars.

Here is a link that might be useful: Root Cellar Basics

I also had a cellar made of old freezer. It worked fine, except one spring the water that came from melting snow pushed it up from the hole I had dug for it. That was a spark to me to build a decent cellar.

My neighbour had a payloader on his yard and I managed to get him make a big (I mean really big) hole in my yard. I built the damned cellar for three years, spending my holydays there...mixing congcrete by hand etc.

Every spring I had to pump water from the hole, which was a little annoying thing, but now the cellar is done, ot has been ready for about 5 years, and no problems of excessive water is to be seen.

I will make a page of this subject to the net, in a couple of weeks or so, if you are interested. I have some photos, too.

I'm also thinking for years already to build a cellar out on my acreage.
I was thinking go the easy way, just buy a pre - fabricated concrete cast, like a tank
with the bottom open and buried it into the ground.
I think it would be a bit expensive.
klematix, your plan would be welcome!
Konrad