All four (if you peer closely) back in their old enclosure which will no doubt be re-furnished to enable them to climb. Male, Yengo, likes to sit on this pole to get a good view into the keepers' kitchen.
@Gigit Being a more terrestrial species, they should be fine for a little while. As you've said, I do suspect that they will add some climbing apparatus in the near future. Their indoors is superb though, how's it looking after a week of use/access?
@ThomasNotTom It's a little dishevelled, lots of the leaves have dropped and I think there were plants in 'your' soil? They seem to have gone, but otherwise it's looking good