Gurumapa

Ghode Jatra's explanation for itself is a demon.

Local folklore names him Gurumapa and puts him at Tundikhel, in the southern reach of the parade ground — in some tellings living in a tree there, in others buried beneath it. What every version agrees on is what he did: he took children, and the city was afraid of him. The racing of horses across the ground is said to keep him pressed down and unable to rise. The noise and the weight are the point.

Stories about Gurumapa circulate in more than one form in Kathmandu, and he also turns up attached to the old Itumbahal tale of a household ogre bought off with an annual feast; the versions have borrowed from each other over a long time and the accounts told today do not fully agree. Treat the demon as the festival's own account of its origins rather than as a single settled legend.

What that account is really doing is making sense of a strange fact: a vast empty field in the middle of a dense city, which nobody has ever been allowed to build on. A demon underneath it is as good an explanation as any.