Wednesday 9.30am, and there we were at the window of Caesar's bunker waiting for the doors of her den to open into her brand new world. The enclosure looked superb. Our ex-Architect, Darren Seng, and Project Director Boris and his team had done a truly remarkable job in creating two appropriate areas which could both enrich and stimulate Caesar, Benji and Poupouce, and which could also provide an educational platform from which viewers could observe.

Media were poised with their camera's and just about half of our staff had come over to see how the bears would enjoy something which had taken many months to construct.

In fact Bear manager Donata decided that the two Tibetan brown bears would come out first - and the den doors opened. Poupouce was first. She had been so nervous yesterday as she'd been moved from her old den into the new - but today she was intrigued by the new scents and sights around her, and out she came.

Benji followed and the two of them sniffed their way around the enclosure clearly both surprised and pleased by all that it offered. At one point Benji had a magnificent burst of energy as he ran across half of the enclosure with the wind in his fur. After just a few minutes however, they both seemed to have a change of heart and walked back into their dens as if they had now both realised that something was very very new and strange - and it might just be wise to retreat for a while to the safety of their dens.

Now it was Caesar's turn - and the hush around the enclosure was "deafeningly" quiet as we all held our breath. The door opened and her nose peered out. Then up the stairs she came; her huge body swaying from side to side as she mounted each step from her "lair" and out on to the grassy embankment above. Looking up at Boris on top of her den, I smiled as he gave us the thumbs up and knew that he'd be more relieved by the second that his construction decisions and safety protocols had paid off.

Caesar is magnificent and there was not a single person there who was not awed by her beauty and majesty as she began walking around the perimeter, checking every inch of her new and permanent home.

Tasty dried fruit, eggs, even her normal breakfast were ignored as she explored some more. Bypassing trees, platforms, rock formations and her pool, suddenly she "found" what she had been looking for - her very own bunker, designed by a team who had anticipated her winter needs and felt she needed a den of her own.

Mission accomplished. I could hardly write the notes through blurry eyes - there was our magnificent Caesar digging in the bunker, down and down with earth flying in all directions as she made her new home. I smiled hearing Nic call out to Donata on the walkie talkie "we'll have a failed recall tonight" because I knew she was probably right. Once she has the choice of staying outside or returning to her den I think Caesar will choose to sleep under the stars.

At one point she and the two brown bears stopped what they were doing and just looked at each other through the chain link fence. Their previous enclosure had only allowed access for either Benji and Poupouce or Caesar to be out at any one time and this was so different as they peered at each other walking around adjacent enclosures. Caesar looked up and down the fence - checking out the "hot wire" to the point where Boris was heard to say that he was confident that all of the bears had "respect" for the electric strands. I took the opportunity to whisper across the walkie talkie asking how he felt about the release and just heard him gulp as he said "it's a feeling you can't describe Jill" and we all knew what he meant.

I couldn't help going back 5 years to when we rescued Caesar in the north of China - and saw her wearing her heavy, rusting full metal jacket which covered the hole in her belly and the disgusting bile and pus encrusted catheter snaking out which extracted her bile. For nine long years she and her cell mate Emma had endured the tortures of the trade, and now here she was today, breathing in the sweet smell of freedom with a calm happiness we could all "feel".

Boris and Howard our Bear Team Supervisor were leading the rescue back then - and we had the most amazing three day journey "home" by road. So it was also special to hear Howard say on his birthday today "I'm happy because Caesar is happy too".

And so it went on - Caesar carried on exploring, momentarily tripping over the poolside rocks, plunging her head into the waterfall and at one point ripping down a paper bag from a tree which had been lovingly filled with honey by Team leader Ou Jun, but always returning to the place she loved the most. I thought how lovely it must be to have a playroom all to yourself where you can make as much mess as you like and no-one will tell you off.

And as I left her to catch the flight back to Hong Kong I looked back to see Caesar at her happiest - digging in her beloved bunker and doing what comes naturally for all brown bears.