Hello,
We are going to Hever Castle in Kent tomorrow morning.However, it does not open until 12:00. Any suggestions of what to do in the morning? We are leaving from East Croydon.
Thank you,

Well, Kent is a big county and there is a lot to do...Hever, on the other hand, is pretty small: I assume you are there for the Boleyn Castle?

You might find it useful to also source out things you want to see and do in either of (Royal) Tonbridge Wells or Sevenoaks. If you are interested in the Bloomsbury Circle (Victoria Sackville West/Nicholson, Virgina Woolf and all that) you will find Knole House of great interest, at Sevenoaks. It is one of THE great country houses.

And if this isn't your thing, Sevenoaks also has some fine pubs for afters: those Boleyn girls can make you thirsty!

Yes, we are there for the Boleyn Castle

Chartwell opens at 11:00 (the cafe opens at 10:30) and Penshurst Place opens at 10:30. Both are very near Hever so you could do one of them first and then get to Hever around lunch time.

Both are VERY worth a visit. In fact I like both better than Hever, though Hever is right up there too.

in any case nothing at all near Hever Castle itself except bucolic countryside

no town, nothing