Apparently La Roca (the rock) refers to their mattresses. Slightly softer than the floor, but only slightly.
Otherwise, this place is Great! Location right on the Plaza Mayor is perfect. Free parking in a nearby secure lot. The hosts are very accommodating and pleasant. The facility is a colonial house that is huge, stretching far back from the square with two lovely courtyards inside, one of which is chock full of plants and flowers. It's delightfully quiet. The breakfast was good. Wish it had some fruit.
In all, a great place to stay if you can tolerate a beyond-firm bed.