The following text is from the original listed building designation:
EYNSFORD LULLINGSTONE LANE 1. 5280 Lullingstone Icehouse in grounds of TQ 56 SW 5/69 Lullingstone Castle II 2. C18. Round-arched entrance of rough flints with barrel vaulted brick chamber behind. The internal chamber of the icehouse is sealed off.
Listing NGR: TQ5301664385 (1)

Description from record TQ 56 SW 91 :
Ice house in grounds of Lullingstone Castle, Lullingstone Lane, Lullingstone. Grade II. 18th century. Round-arched entrance of rough flints with barrel vaulted brick chamber behind. The internal chamber of the icehouse is sealed off. (2)

At Lullingstone, the ice well, TQ 533 645, is located in a wood overlooking the River Darent. It has an inner cavity to act as an insulating panel and a barrel vaulted passage with two entrances to the crawl hole which leads to the well chamber. (3)

<1> English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.

<2> DOE(HHR) Dist of Sevenoaks Kent Oct 1982 24-26 (OS Card Reference). SKE40996.

<3> KAR 56 1979 126-7 illus (J Blundell) (OS Card Reference). SKE45368.