The Sri Yantra is the most popular yantra. It is a complex geometric representation of the Sacred Feminine

The 'Durga Beesa Yantra', seen at the bottom of most pictures of Mother Durga.

Ganesh Yantra

Gayatri Yantra

Hanuman Yantra

Kali Yantra

Swayanvara Yantra

Vishnu Yantra

A neon-blue version of the Shri Yantra