[FEL-L] Lion enclosure design

[Tim Stoffel]

To all the good feline folks,
    I have been asked to design some lion enclosures for a new facility.
One feature of this facility is some fairly sizeable open-top
enclosures. Traditional wisdom from my limited experience has been '16
foot high with a recurve'. What has worked for you? Can you point me to
any 'official' guidelines from AZA, etc.? How about interior walls
separating two enclosures from each other? Any novel materials for the
fencing? The people behind this are very serious about doing this right,
but are not afraid to innovate.
    A couple of other questions: How high should a closed-top enclosure
be? What kind of construction would you use for a den box that is
exterior to the enclosure?
    Any and all ideas are wanted!

Thanks in advance,
'For the lions'
Tim Stoffel