There's not much of the castle, as a castle, left -- the only original part is the medieval gatehouse and parts of its two flanking towers -- and it was reconstructed in the late fifteenth century as a country manor by Geoffrey Bullen, the grandfather of Anne Boleyn....a name which points to the reason for the castle's notability. Much of what one sees there today (apart from the exterior work) is the product of the restoration undertaken before the First World War by the wealthy American William Waldorf Astor, indulging his love of things European and medieval to create a neo-period family residence. (On the other hand, if you had the money you'd probably indulge that sort of fancy, too.) He also laid out the present grounds, transforming empty meadows into a series of gardens and a boating lake with a loggia and a fountain modelled on the Trevi Fountain in Rome.
We bought a guidebook, we visited the castle, we strolled through the gardens and (to finish) walked around the lake. We also made a short visit to St Peter's Church in Hever village, where Thomas Boleyn is buried, before catching the train back to London. Here are some photographs: of Thomas Boleyn's tomb chest in St Peter's Church (you will note that the carvings are in very poor repair, and that brick has been used to support part of the chest); a general view of the castle itself from the southwest, showing the medieval gatehouse and the exterior walls of the late medieval manor behind it; part of the Tudor gardens; a view of part of the rose garden, with the Wugster at far right, in the distance, about to thrust her proboscis into a flower (note also the yellowness of the grass, thanks to the summer drought -- something which is almost unheard of in these parts, doncha know); and a view of the loggia from across the lake.