Atop

on or at the .
on the of:
atop the flagpole.
contemporary examples

atop her head sat an upturned, dented little metal bucket—recycling turned into millinery.
paris fashion week: redefining femininity at comme des garçons and rick owens robin givhan september 29, 2012

ilyumzhinov, a former governor of the russian province of kalmikya, has been atop the federation since 1995.
chessmaster garry kasparov is determined to checkmate vladimir putin eli lake june 16, 2012

the head of this family, atop his roof with the rest, poked his head gingerly above the parapet, fearing the worst.
michael ware on staff sgt. robert bales, accused of killing afghan civilians michael ware march 19, 2012

atop each page of his notebook mccartney would scribble another lennon-mccartney original.
the beatles succeeded through talent, ambition, and a lot of arrogance andrew romano november 9, 2013

luckily for henry the guy giving orders from atop the sirens of the lambs truck spoke in a british accent.
has banksy been identified? justin jones october 15, 2013

historical examples

and now lay one atop of the other, and you have it––an invention of my own––a blueberry sandwich.
the seiners james b. (james brendan) connolly

“drop her atop of the little rock as i say when,” growled josh.
menhardoc george manville fenn

the others were tied together and one end made fast to a big stone—a loose one atop of the wall.
charge! george manville fenn

presently will stumbled and fell, pulling down robin atop of him.
robin hood paul creswick

atop this the snow suddenly grew deeper and the ascent more precipitous.
the killer stewart edward white

adverb
on top; at the top
preposition
on top of; at the top of
adv.

1650s, from a- (1) + top. two words or hyphenated at first; not fully established as one word till late 19c.