We rescued three kitten siblings a few years ago and, until they grew older and more independent, they generally slept together in this large cat bed.... Or sprawled over the sides to play with their toys without getting up.... Or just hid behind the high sides until they could jump out onto (literally) one of the older cats as they walked unsuspectingly by.
It came up well on each of its many trips through the washing machine and was the favourite place for the kittens to sleep, particularly as it comfortably accommodated them all together as they started to grow - as well as the middle cat, who seemed to act as a surrogate mother to them and joined them on occasion (when it was a bit more of a squeeze).
The bed had to be retired when it was damaged during a stay in a cattery but I will be getting another when we decide to add more kittens to the brood. The high sides on the bed helped the kittens settle in as it seemed to make them feel safer than the others we had at the time. It was also easy to wash, as well as quick to dry again, whenever any of those little accidents happened.