Before the invention of refrigerators and freezers, many country houses would have a ice well. These would be brick built with a domed roof and would be built into the ground. The ice, which would be cut from a nearby lake, would be packed inside. The well worked by keeping the cold in and excluding the warmth,and thus ice was available to house all year round. Experiments have shown that ice in these wells could remain frozen for up to 2 years.
The example which we have now in Tarn Park was the ice well from nearby Eltham Lodge ( now the clubhouse of the Royal Blackheath golf course) and dates from around about 1760.
Pete's Favourite Things 
This brings back happy childhood memories for me. My grandfather was the first park keeper at the Tarn from the 1930’s to the 1960’s and I spent many happy hours there. The ice well was fully open then although behind railings, and held a strange fascination for me.
No park keepers now. Most of the work is done by a group of volunteers ‘The friends of the Tarn’
So sad to hear that. Many years after my Grandads retirement I met Mr & Mrs Moore, who were my Grandads successors and lived in the lodge. They were a lovely couple, very nice to me and my husband. So glad volunteers are keeping going this lovely oasis. I still feel rather possessive about it, silly really. I have so many happy memories which no one will ever be able to take away.