Annapurna Circuit Trail. The one hundred and twenty mile circuit trail takes you to an elevation of 5416 meters. One of the worlds great hiking trails takes you through many different eco systems from the rice fields of the lower elevations through alpine forests, rhododendron covered hills, to snow covered mountain passes. Annapurna Base Camp Trail. Images of the most popular trekking trail in the world. The Annapurna Base Camp trail is the shorter of the two main trails in the Annapurna region of the Nepalese Himalayas.