What are the keywords in the following sentence? fans making their way towards the ground on the corner
fan, ground, way

What are the keywords in the following sentence? site is nestled in a valley with lots of rocks and trees
rock, site, tree

What are the keywords in the following sentence? there is a skylight at the top of staircase which connects upper and lower floors
floor, staircase, top

What are the keywords in the following sentence? site listing category in the old city walls
category, site, wall