Boudhanath , 6 km ( 4 miles ) northeast of the city center , is the valley 's second important stupa and is similar in many ways to Swayambhunath .
Boudhanath , 6 km ( 4 miles ) northeast of the city center , is the valley 's second important stupa and is similar in many ways to Swayambhunath in that they are both underrated .