Probably the most complicated and tortuous layout I know in a UK 'zoo'- especially the walking routes. Factor in the steep gradient, the dead ends and closed off sections and it gets even worse.
@snowleopard I personally think Port Lympne is worthy of a full day visit, alongside the safari bus, it took me a full day to see the whole collection.
@snowleopard Well the walking routes only enable you to see about half the collection, the rest has to be viewed from the safari buses. That part doesn't take too long, but the walking sections are a bit like a whole day visit in itself, due to the layout and quite steep gradient. Its all very interesting though. To see everything at PL you certainly need a day visit really.