The frogs are being kept in a refurbished shipping container: http://www.zoochat.com/60/frog-breeding-container-166391/ This is the sign they had displayed when I was there last June: http://www.zoochat.com/60/signage-166438/ Hix
Probably an Amphibian Crisis biosecure unit. Nice to read that this endangered frog species is getting the headstart treatment .. and that captive-breeding has succeeded (even more important).