mysterious stone carvings?

Well maybe not so mysterious but I find this simple carvings incredibly moving. They are such a strong connection between the past and present . I have even thought about adding my own carving in 2015 but what symbol should I choose? As an atheist it wont be anything religious but it could be spiritual? I'll need to think it over.

 

 

This cross is carved on the entry to Santa Maria Arrabona- sadly the local limestone is easily affected by the weather so many of the lightly incised line are very hard to see however the criss crossing pattern of many different carvings can just be made out and is very similar to our stones in Contrada Foce

One of the strangest of these symbols must be these weird foot shapes! Actually they were carved by pilgrims as a sign pilgrims were welcome (?) or as a form of early graffiti 'I was here'?

The Flower of Life is found carved in many local churches including The Santa Maria Di Arrabona and San Liberatore in Serramonacesco. There is a significance to the number of petals in the flower: They represent the 6 days of Christ.
http://www.luoghimisteriosi.it/argomenti/fioredellavita.html