The Manaslu Circuit is one of Nepal's lesser-known treks. It's adjacent to the more popular Annapurna Circuit – which is just west of the Manaslu Circuit – and the (typical) end of the Manaslu Circuit is also the (typical) start of the Annapurna Circuit in Besi Sahar. The treks share the same route between Besi Sahar and Dharapani.
You are required to bring a guide and to have a trekking group of at least two people to hike the Manaslu Circuit. This is one of the reasons it's not as popular as the Annapurna Circuit (which you can trek solo and without a guide). That said, the Manaslu Circuit is arguably more impressive and a better experience than the Annapurna Circuit.
The following collection of photos from the Manaslu Circuit – including the Tsum Valley side trek – begins in Arughat Bazar and ends in Besi Sahar.