For Grotto use a square notes paper size 9x9 cm (3 1/2 x 3 1/2 inch). The cave and all shown models are part of a book "Opowieść bożonarodzeniowa z szopką betlejemską origami" by Barbara Furmanowicz. Look also at Kneeling Mary ...
by JeremyShaferOrigami
by How to... Science, Craft Plus
by DIYwithME
by Origami library
by happyfolding.com - enjoy origami
by trpattern
by Paper Folds - Origami & Crafts !