ZX81 'Caverns' Game - PC Remake
Author of the original 1980's 'Caverns' game offers a PC remake for download. Includes game history and instructions.
http://www.users.globalnet.co.uk/~mart03/zx81.htm

Ekosystem
Ekosystem caverns, tunnels, underground facilities and harbour
http://www.ekosystem.net

BCT Consultants
Designing petroleum and petrochemical storage, including LPG storage caverns.
http://www.bct-consultants.co.uk/

Conversion Gas Imports L.L.C.
Licenses patented technologies for the receipt, storage, and distribution of ship borne liquified natural gas or LNG. Includes information about the technology, salt caverns, and heat exchangers used.
http://www.conversiongas.com/

DreamDesign Vue Explorations
Items in Varian's Dreamview cover digital artwork of many types, including backgrounds and wallpaper for desktop or the web, borders, tutorials for making your own effects, Blade Pro presets, a collaborative artwork section, fractals, 3D models in RDS and DXF, shaders for Ray Dream Studio, stationery for Outlook Express and a lot more!
http://www.varian.net/dreamview/dreamdesign/evd/index.html

Kentucky Down Under and Kentucky Caverns
Horse Cave. An Australian themed animal park and cave with onyx formations. Includes photos, descriptions, and visitor information.
http://www.kdu.com/

Solution Mining Research Institute
Site includes basic information on solution mining for salt, current research on solution mining technology and technologies for safely sealing and abandoning mined caverns, and information on association activities and conferences.
http://www.solutionmining.org/