A selection of simple celtic knots. As requested, I've now added each of the knots separately - nicknamed according to their position in the thumbnail (top or bottom row and numbered 1-3 from left to right). Enjoy!
This image was donated by Pearson Scott Foresman, an educational publisher, to Wikimedia Commons, and is thereby in the Public Domain.
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See http://commons.wikimedia.org/wiki/Category:Pearson_Scott_Foresman_publisher
A remix of http://www.openclipart.org/detail/631 originally derived from the US government EPA "Sunwise" program. I converted it from PDF format. the source link is here - http://www.epa.gov/sunwise/doc/poster.pdf
There is more detail on the doors.
