Old classics

I have sorted through some never- to-be-thrown- away- classics from my shelves- and lately re-reading the Green Knowe series.  My copies were hunted down from op shops, book sales many years ago and I have the whole series- wonderful.

I love the fact that the author L.M Boston only  began to be published when she turned 60- hope for the older writers amongst us.

Why is this such a classic?  For me it's the timelessness of the themes- granted some language may be dated but the forage between history and present time is fresh, the themes covered are pertinent and the writing seamless.

What classics do you read and re-read?