Best play farm for a toddler group?

[AllBuggiedOut]

After receiving great advice from Mumsnet about which kitchen to buy for our baby and toddler group, I thought I'd ask about farms too! We have masses of plastic animals, but the farm to put them in is very old. Can anybody recommend something sturdy and durable? The ome we have is just a few farm buildings fixed onto a board approx 60cm square, which is great because it can't get knocked over, and doesn't need any setting up, but I can't find anything similar.

Adevice appreciated, thanks!