Playpen.

Set up a playpen at my house today, Alexandra has an almost identical one at hers.  It's pretty big, and has a little gate, so you can walk in and out of it.

Isabella was quite happy sitting inside it, and played for ages on her own.

Sophia was very interested in it, she played with the bars, had a chew at some ties, holding in the play mat.  Then she got up on the cat picking post to see if she could jump into it.  We managed to stop her, and she seems to have lost interest now.

Neo had a sniff and a look, but didn't seem too interested.