Hi Steve,
Sorry it's taken me a while to get back with map refs. All from 1:50,000 (or 1 1/4" to the mile if you're like me, sheet 203) Most have 'Chy', 'mine, etc marked.
Trewavas Head/Rinsey: SW600265
Crowns Mine & Wheal Edward: SW362337 (an area of intense mining activity - plenty of ruins!)
Levant Mine: SW368345 (National Trust and in steam sometimes - check NT website. no need to spend any money if you just want to look from the outside!)
Pendeen Watch: (Lighthouse) SW379359
Cape Cornwall: SW350318 (England's only Cape - headland with chimney stack on summit)
If you get a rainy day (not unknown in Cornwall!) Geevor Mine SW375345 is a tourist attraction but well worth a look. I had the good fortune to go underground here when it was still in operation in 1986. The parts of the mine that we collected specimens from were in levels driven out under the sea bed and are now sadly under water.

Have a good time!